unit 3

Newton's third law states that every action has an equal and opposite reaction.
It is important to recall how impulse is connected to momentum with the F component.


So when two cars collide, the forces are the same and opposite.
If the forces are the same and opposite then their momentums are the same because of F.
If the forces and momentum are the same, then their impulses are equal since change in m=J.
The only thing that is different is the acceleration.
F=ma

The truck has a big mass
Truck=   F = Ma
Car=  F = mA

if the car has a small mass, then the acceleration is going to be bigger. (Newton's second law)



momentum is mass times velocity

mass is usually constant, so velocity can sometimes change. Remember that velocity can change because any change in velocity is acceleration. So that is why we have change in momentum.
Change in momentum equals impulse. Now impulse equals force times the change in time. How are these two connected? Well remember that velocity can change? And that this change is called acceleration? Acceleration requires a force, and that is where we get the F in impulse's equation.

p=mv
change in p= J
J= F x change in t

Why do air bags keep us safe?

When you are driving in a car and you crash, you go from moving to not moving. Remember that momentum is p= mass x velocity.
However the change in momentum equals pfinal- pinitial. This is the part I was talking about. You are going from moving to not moving. Now matter how you are stopped, you will go from moving to not moving, so the change in momentum will always be the same. If the change in momentum is the same and since change in momentum = impulse, then impulse will always be the same. The airbag increases the change in time. Remember that J= F x change in time. Therefore if the change in time is increased then the force is decreased because impulse is constant. Then the force on you is decreased and you will have less of an injury.

p=mv
change in p= pfinal-pinitial
change in p= J
J= F X change in time

Now... for the change in momentum:
 a car with a mass of 1000 kg starts form rest and gets up to a speed of 100m/s. what is the impulse?

change in momentum = pfinal-pinitial.
What we haven't said is that pfinal= mvfinal
and pinitial= mv initial.

SO
1000 (100)- 1000 (0)

SO the change in p = 100,000 kg m/s

or J= 100,000 Ns

Incorporating Impulse into this problem we add a change in time

So.. if the car was moving for 10 seconds what was the F needed to cause that same change in momentum?

J= F x change in t

Change in t= 10s
J= 100,000 Ns

so... 100,000 Ns/ 10s = 10,000 N

10,000 N= F

What if we had two cars? and what if we wanted to know what their velocity was after they collided?

Ptotalbefore = Ptotal after

Ma Va+ Mbvb= Ma+b x (Vab)
solve for Vab

you have to add the momentums together and the masses together to get the speed

this equation is actually just the same version as p=mv
but p you are adding the momentums, m you are adding the masses, and V includes both velocities.


You know how momentum is when something starts and stops? Well when I ball bounces, it is starting and stopping... but then starting again. This requires 2 impulses. An impulse to stop... and an impulse to start up back again. Remember how impulse equals F X change in time? Since force is needed in impulses, then that means you have 2x the force since you have two impulses. If you have 2x the force, then if a ball hits you and bounces off it will hurt more than if it hit you and stopped. Same with bullets. This is why cops have bullet proof vests that stop the bullet rather than make it bounce off them.

We've talked about impulse/momentum and their relationships. We've talked about the change in momentum. Now lets talk about conservation of momentum.
There was a question on a quiz that said to prove that momentum is conserved.
one example is from the lab when one cart was moving at  a cart sitting still. The moving cart might have 8N and the cart at rest has 0 N. When they collide and move together, they have 8N. This is how momentum is conserved. Now the question asked us to prove newton's third law.
the equation was y=2.9333+ .3778

If Cart A has a mass of 2kg... and Cart B has a mass of 1kg... 2+1= 3

you can rule out .3778 because it is so close to zero

here are the steps:
write out the equation of the line (which we just did)
fill in the y axis units...
remember that equation we did before?
Ptotal before= Ptotal after?

MaVa + MbVb= Ma+b (Vab)

when the carts collide we are adding their masses and velocities together like we said. so that is why we have to add 2+1 like we said

basically when we translate the equation from y intercept to the mava one.. we get that y= p total before

and x is the VAB
and the 2.93 is the masses added together

because that's the same equation right?

ptotal before= total mass (total velocity)

MaVa+ MbVb= total mass (total velocity)  +  over here would be the .3778 but its too close to zero..

these are the separate cars= and you are adding them together

we compare the 2+1 to the 2.93 and we can comfirm newton's law.



Show how the conservation of momentum is derived from Newton's 3rd law+

Fa= -Fb
(all reactions have an equal but opposite reaction) (forces are equal but opposite)
there are forces in impulses
so...
Fa x change in time= -Fb x change in time
so..
Ja= -Jb

so since J equals the change in momentum..
change in Pa= -change in Pb
if you add -change in Pb to the other side it equals zero
so no total chnge in momentum of the system
or no net change
so momentum is conserved.

we just went from newtons 3rd law regarding force and since forces are needed for impulse we added impulse to the equation and since impulse is equal to the change in momentum, we added momentum. From there we can say that momentum is conserved.

Okay enough of momentum.
Let talk about the universal gravitation equation.
 F= G m1xm2/ d squared.

BIG QUESTION: why is the moon responsible for the tides if the sun exerts a larger force on the two sides of the earth than the moon does?

It is the difference between the forces exerted on side A and side B from the sun that are less than the difference in the forces exerted on side A and B from the moon.

So what do we know?
everything with a mass is attracted to all other things with a mass
force is direction proportional to masss
force is indirectly proportional to distance
 the less distance you have from the center of the Earth, the greater the FFORCE
F= G x m1xm2/dsquared

F= weight
G= universal gravitational force
m1= earth mass
m2= your mass
dsquared= distance between you and earth


Earlier we calculated weight by doing w=m(g)
and from there we find acceleration
a= fnet/m
Now  since we find weight using the ug equation
and weight equals fnet in the acceleration equation,  we can compare w and F to see if you get close to your weight  and your actual weight(gravitational equation)



Here is a video explaining tides:


This video shows how tides are formed from the interactions of both the sun and the moon. We know this to be true from the universal gravitation equation. That force is inversely proportionate to distance, and even though the suns mass is larger and therefore has more force on the moon, the difference in these forces of side A and side B are less than the difference of forces on side A and side B of earth and moon.



This unit seemed to be a bit jumbled. Connecting tides with momentum..? Yeah I wasn't sure how to approach that one. I feel like I was a bit more on top of things this unit than last unit. I hope that next semester with a fresh start I can reorganize my thoughts. I did not have trouble processing and learning this time around like I did last time.. so that was good. I really enjoyed learning about this unit and making the connections that I could in this blog.

tides

This video shows how tides are formed from the interactions of both the sun and the moon. We know this to be true from the universal gravitation equation. That force is inversely proportionate to distance, and even though the suns mass is larger and therefore has more force on the moon, the difference in these forces of side A and side B are less than the difference of forces on side A and side B of earth and moon.

Unit 2 Blog

Unit 2 Blog

Newton's second law states that acceleration is directly proportional to force and indirectly proportional to mass, or a= Fnet over mass. We already know that if a n object has a force of 10 n action on its left side and 10 N acting on the right side, you cannot say whether the box is at rest or whether it is moving. But, we do know that the box is not accelerating. The point is that we are trying to prove the first part of the equation: that Force is causes acceleration. Force is directly proportional to acceleration so if the net force is zero on this box (because when you subtract to get the Fnet, both sides are equal so when you subtract you get zero) that means that there is no force overriding the opposite one since they are both equal. since this is not happening and a is directly proportional to fnet and since fnet is zero, then the acceleration is zero.  So Newton was right: a is proportional to f.
Since we know that forece causes acceleration, if we had a box with 10n pushing to the right on a fricionless surface, the net force is 10n and therefore since force causes acceleration we can see how the force of the box affects the box. If the netforce was zero, there is no force so the box does not accelerate. If the netforce is 10n, then this causes acceleration.  if force increases, acceleration increases; if force decreases, acceleration decreases.  Now for the other part of Newton's Second Law. Remember how it was faster for a person with less mass to ride on the hovercraft? This scenario exhibits the nature of the inverse relationship between mass and acceleration. If there is more mass, there is less acceleration; if there is less mass, there is more acceleration.

Since the equation is a= f over m and you want to find the acceleration you have to divide the force by the mass.

What if the object is traveling downwards? This  is where weight comes in to play. Weight=mass times gravity. If you have an upward force acting on the object, then you must first calculate the weight for whichever is not given) using w=mx g take that number and then subtract it form the force moving upward

So if a box was 10kg  and the upward force is 20N, what is the weight? Mass= 10kg x 10 so the weight is 100N. Then you do 100 minus 20 and you get 80 and that is the fnet. To find the acceleration  of this box, you must then divide 80 by  10kg. Finding the Fnet is just the same up and down as it is side to side. The only difference is that you need to incorporate gravity in this problem since is going up and down hence weight= mass x gravity.

The lab also demonstrated Newton’s Second Law. Firstly, you need to know that when you find the mass you have to find it for the entire system.  That means that you add the weight of the cart, the weights in the cart, and the hanging weight.  Remember that the net force is equal to the weight, and since the only force acting on the hanging weight is gravity, you take the mass of the hanging weight and multiply it by gravity.  You can also find the acceleration of the cart by using a= force over mass.  Remember but force is actually fnet, or the net force of the system.  If you graphed the data that you found for the experiment, you must translate the equation. Remember that the slope is always constant. So whatever element is constant in the equation. We Know that the net force is constant in the system in the lab. So we know that in the given equation, 28.89 is close to 30N (net force). Therefore, Newton was correct.

Sky diving also reinforces Newton’s second law. Since force causes acceleration, fweight causes you to accelerate toward Earth, therefore you speed up.  Fair is the air resistance in skydiving.  The fair is directly proportional to speed. Fair is directly proportional to fnet or basically it is proportional to when you subtract the fair from the fweight. If the fnet goes down, meaning the fair and fweight are getting closer, and then the acceleration goes down. However, you are still getting faster because while the acceleration may be going down it just means that you are not getting faster as fast as you were before. It is just like the ramp scenario.

Eventually the fair catches up with the fweight and you hit terminal velocity. At terminal velocity, you have reached your maximum speed. There are two things that affect air resistance: speed and surface area. When we pull the parachute to slow down, the air resistance increases and the fnet increases. The air resistance increases because we have more surface area. The fair eventually returns to terminal velocity, this time at a slower speed. So what causes the air resistance to increase when an object is falling: the parachute increases the surface area so fair increases.

When someone kicks a ball off a cliff, the ball falls at an angle. Its horizontal velocity is constant and the vertical acceleration is also constant: increasing at 10m/s.  every second the ball falls at an angle by the constant horizontal velocity and by 10m/s. To find the vertical distance, we use d=1/2 gtsquared. This is most likely going to be the height of the cliff. It also determines the time the ball will have in the air. To find the horizontal distance, we use v= d over t. You can make a triangle from the speed of the horizontal velocity and the vertical velocity. We can have either 3.4.5 traingles or  triangles with two identical sides and one x root 2 side.  Root 2 stands for .141.  Sometimes you will need to use Pythagorean thyrem to solve for the sides.  All of theses tactics help you find the actual speed of the ball.

When we throw something straight upward, we are dealing with only vertical velocity. Since we know that vertical velocity increases/decreases by 10m/s we can say that for every second the ball is travelling upward, it has increased its speed by 10m/s. The most important factor is that its acceleration will always be 0 m/s at the top of its path. Just like when we hit a home run, and we want to know the speed of the ball at the top of its path, the ball must be only moving with horizontal velocity because there is o m/s vertical velocity. Most problems dealing with throwing a ball straight up want to know either the vertical distance or the time the ball was in the air. 

I found this unit pretty challenging. I loved it though. I noticed how much of a problem it is if you accidentally miss an assigment, and I feel like the time crunch of this week also hindered my understanding. However, I know that I did my best to complete my work and I plan to do better next week staying on top of my work so that I can understand at a better level. For some reason, and I really couldnt figure out why, but it was like my brain was just actually cotton ball during this whole week. I struggled to make connections and comprehend and also to envision how to make the podcast. It was a struggle bus week. Hopefully, with more time, next week I can accomplish more. 

In projectile motion, this video shows that both balls hit the ground at the same time. Why? because you substitute acceleration in the equation d=1/2 a x t(squared) with gravity which is 10m/s d= 1/2(10)x t(squared). Since there is no air resistance, then the weight of the balls don't matter and gravity is the only force acting on them, and therefore they hit the ground at the same time.

Newton's second Law

Newton's Second Law







When the man hits the bell thingy, its shows how force is directly proportional to acceleration. Newton's second law states that acceleration is directly proportional to force and indirectly proportional to mass. When the man pushes the two people on the swings, we can see that the larger man does not go very far on the swing. Therefore we can prove that mass is indirectly proportional to acceleration because the more mass you have, the less acceleration you have.

Unit 1 blog post

When you ride in a car and you toss a penny upward, where does the penny land? When trying to find the answer to this concept, I got lucky and guessed that the penny will land right back in your hand. I had made an educated guess, but the reason the penny lands back in your hand is more significant. The penny lands in your hand because of Newton’s First Law: An object at rest tends to stay at rest and an object in motion tends to stay in motion. Now you might wonder how this could possibly relate to the penny. Well, there is another part of Newton’s First Law- the exception. An object at rest tends to stay at rest and an object in motion tends to stay in motion IF no outside force is acting upon it. The car is a closed system, and therefore no outside forces are acting on it. So as the ball pops upward, it continues to move at the same speed as the car.

When you rip the tablecloth from under dishes on a table, why do the dishes stay? Well, we know that the dishes are at rest on the table. According to Newton’s law, objects at rest tend to stay at rest. However, that is not the only reason the dishes stay. The dishes have a greater mass than the cloth, and therefore a greater inertia, so it is easier to move the cloth than the dishes. This relates to another question posed in the classroom. Why, on a hovercraft, is it harder to stop a larger person than a smaller person? When we talked about the dishes’ unwillingness to move, we were referring to their inertia. The more mass an object has the more force you need to move it. Therefore, inertia is the amount of force needed to move or stop an object. Another example of inertia that baffled me most, was the question about a box and a car.  Why would a box inside of a car hit the back when the car accelerates? At first I thought that the force of the car accelerating was what made the box hit the back. I was wrong. The box was at rest, therefore it would want to stay at rest in the same spot. When the car accelerates, the box does what It was happily doing the whole time. The box stays in the same spot and the car moves forward and therefore the box hits the back of the car.

   SEE HOW THE BOX STAYS AT THE SAME POINT????

We also learned about why a hovercraft is in equilibrium, what equilibrium is, and what it takes to have it. Equilibrium is when an object is either in constant motion, or at rest. There can never be friction because the Net force, or the total force, must be zero. Friction is one element that can be called an “outside force”.  Equilibrium is the very essence of Newton’s First law. Equilibrium at rest wants to stay at rest; Equilibrium in motion wants to stay in motion. However, the only thing (that we know of so far) that would get in the way of equilibrium is friction. The “thing” that starts equilibrium is force (a push or pull).

A hovercraft is pushed at the beginning (force) and then can “glide” because there is no friction. The net force at this time is zero and therefore it is at equilibrium. It takes as much force to start an object as it does to stop it. The latter part of a hovercraft’s journey is the stopping part. The force to start the hovercraft is the same amount of newtons used to stop it. Force is measured in newtons.

The math:

Net force is measured in newtons right?

So if I pushed on a cart with 50N to the left and my friend pushes on the cart to the right with 5ON, the net force is zero N because 50 minus 50= zero

More about hovercrafts:

Hover crafts combine Constant Velocity and Acceleration all in one.

When you push the hovercraft it accelerates. The hovercraft then reaches constant velocity because it is in a frictionless environment. At the end when someone has to stop the hovercraft, they push it backwards. What is the hovercraft then doing? Well it is accelerating backwards or otherwise known as deceleration. When you are gliding, the hover craft wants to stay in motion (sound familiar?), and the outside force that breaks the constant velocity is someone stopping it (outside force).

What is Constant Velocity? Constant velocity is when an object is covering the same amount of distance in the same amount of time at each interval. So if I measured a ball rolling on a flat surface each second, the space between each mark would be the same because the ball is moving at constant velocity. Velocity not only refers to the speed of an object, but also its direction. Therefore, velocity is changed by changing speed or changing direction.

VELOCITY IS ALWAYS CONSTANT

ACCELERATION IS NOT ALWAYS CONSTANT.

The equation for constant velocity is velocity = distance/time. Velocity is measured in meters per second. The difference between speed and velocity is that velocity deals with direction.

Acceleration, however, is the change in velocity over time. Acceleration also has a catch. When you roll a ball down a hill, the acceleration acts differently depending on the hill type. The point is: Acceleration can be constant if it speeding up by the same amount every second. If the hill is perfectly straight: the acceleration is constant- meaning it is speeding up by the same amount every second. However, the acceleration decreases and increases depending on the dip of the hill.

If  the dip is like a fat dude’s belly, then the acceleration increases.

If the dip person is like an anorexic persons belly, then the acceleration decreases.

How do we calculate the rate of acceleration? For example, if a car starts at 10 miles and ends at 15 miles after 10 seconds, then we can calculate this by the change in velocity over time.

So: V= change in v/ time.

However, if we wanted to know how fast the object was going, we calculate it with this equation:

Velocity= (acceleration)x time

Or V= at

If you want to know how far, or the distance an object has gone:

Distance= ½(acceleration)x time(squared).

Or D= ½ a x t(squared)

If you are accelerating, then the speed is changing, and therefore you cannot have a constant velocity. If a car is going the same speed around a race track, does it have a constant velocity? No, because the direction is changing! However, if you are driving at a constant speed around the race track, because you are changing direction, you are also accelerating. WHY? This concept confused me until I dissected the equation for acceleration. Acceleration happens every time there is a change in velocity. Just like the equation insists, you can never calculate the acceleration without knowing the time.

A word about friction: the force of friction is always equal but opposite. So if you push a box with 150 N force and the box is at a constant velocity, what is the force of friction?

It is just like the hovercraft problem. There is constant velocity, so the net force must be zero because constant velocity means the box is at equilibrium. If the hovercraft is pushed with 150N, what is the force that is acting on the other side? -150N.  Therefore, even when an object is in constant motion, the friction force must be equal but opposite. However!!!!! If I am pushing a box at 50N to the right and my friend is pushing at 20N to the left, then the net force is 30N not zero.

I Learned about how the graphs depict constant acceleration and constant velocity:

If you want to know where the line will be on a constant velocity graph:  use y=mx+b

You take the equation given to you when you put the data in excel, and then you translate the equation from y=mxtb to distance=slope x time +b

In finding the distance of an acceleration graph, you DO NOT NEED B. But… in the velocity one you do.

If the question asks where the line will be after 5 seconds, you plug the 5 in for x, multiply that by the slope and then add this to “B”.

BUT- this is not the same as FINDING HOW FAST THE MARBLE WAS GOING. If you want to know how fast, you plug in the V=D/T and that is the meters/second. How fast would it be moving after 9 seconds? It would be moving at the same rate that you got from the equation BECAUSE VELOCITY IS CONSTANT.

The graph of constant acceleration is steeper because you are covering more distance per time over time.  We know this because acceleration covers about 160 meters before reaching 5 seconds while the constant acceleration only covers 109 meters at 5 seconds. To calculate the rate at which the line is accelerating: you use A= change in velocity/time

If you want to make a prediction of how far your marble will have traveled after a certain time- you use D= ½ acceleration time (squared)

½ a  represents the “ slope” in y=mxtb

The b is crossed out because you don’t need it.

So basically D= ½ a x time (squared) is really   y=mx

Remembering that applying this equation within a graphing problem is only helping you predict how far it will go, not what the line will look like once its there. That’s what the y=mx+b is for- To see where the line will cross on the graph if you plug in random times for x.  The distance formula is for numbers, the equation excel gives you is for the visual.

If you need to know how fast for after you have calculated the how far it has gone…

REMEMBER- you need to take the number in the slope and multiply it by 2  EX: D= 3.95x T(squared)

Why? 3.95= ½ a …. And in the how fast equation you need the full a…. not just half of it.

Because the number in the distance formula is ONLY HALF THE ACCELERATION

so… V= AxT

v= 2x3.95 x T

remember to include meters/seconds squared because its ACCELERATION.

SO:

Using y=mx+b is only for graph purposes and translation purposes

Velocity=

Use y=mxtb to translate into v=d/t

Acceleration=

Use y=mx+b  to translate (or rather y= mx)

D= ½ a x t(squared)      mx= ½ a x t(squared)       and y= D

 Back to graphing:

In the lab we switched the x and y axis. For the velocity and acceleration graphs we put time in x and distance in y. Therefore the side would show distance and the bottom would show the time. However, when we wanted to SEE the distance change, like literally see it, then you need to switch these.  So distance would go in the x column and time would go on the y column. 

I worked through the lab without very much trouble, but when I was confused I went in for conference period to affirm my answers in the lab. The purpose of the graphs in the lab only made sense to me until tonight because I needed to find the connection between the equations and the graphs. Why did we make the last graph? I was able to see that we needed to make the last graph and switch the colums for a better view of the distance. Somehow I must have missed this in class. When taking the quiz on velocity and acceleration, I found to my surprise that I was able to remember that no matter how long an object has been in constant velocity, it will still be going the same meters per second  (I didn't fall for the trick question basically). 

Collaborating with Cori in the group project allowed me to better understand translating the equations into words and vice versa. However, it was not until making this blog post that I realized the slope intercept form was used simply for a visual aid and that the other equations were only for calculations. Making these slight corrections in my understand has boosted my confidence for tomorrows test. I hope to create more visual aids in the future since I am a visual learner. Going back over the lab and dissecting why each answer was asked helped me realize on a deeper level what each part actually meant. My effort toward being a student has been exemplary. I think I also have grown as a learner and I hope to continue to work hard so that I can enjoy what I am learning. My initiative to get work done in advance has helped with understanding the material since it leaves time to go back and re- absorb it. 

Lab

        The objectives of our lab were to understand the difference between constant velocity and constant acceleration, to effectively use the data for the velocity and acceleration formulas, and to practice and understand visually what types of situations each are used. Another purpose was to understand what the parts of each equation actually mean, instead of plugging in numbers. The difference between constant velocity and constant acceleration deal with time and speed. Constant velocity is when the object covers the same amount of distance in the same amount of time at each interval while constant acceleration is when the object increases speed by the same amount at every interval. To understand this visually, we used a flat surface to roll a marble and mark its place every half second. We observed that the distance between each mark is the same. For acceleration, we placed the same marble on a table that was elevated at one side. We rolled the marble down the table and marked its place every half second.

        From here, we could observe that the distance between each mark grew by the same margin every half second. When we drew pictures of different inclines and imagined the marble rolling down each one- we noticed that the velocity and the acceleration did not always match.  In a hill that is extremely slanted, we observed that while the velocity continually sped up, the acceleration was not increasing as fast as it was at the very top of the hill in comparison to the bottom. If the incline is perfectly slanted, however, the acceleration is constant and the velocity increases.  If there is a rounded top in the incline, then we can observe that both the acceleration and the velocity are increasing.

        What does velocity and acceleration look like on a mathematical level? We learned that constant velocity is found by dividing the distance by the time. We also learned that acceleration is the change in velocity over the change in time. Which makes sense because acceleration speeds up at the same rate over a changing time  frame. However, if you wanted to find how fast an object was accelerating at a constant rate, the formula is velocity equals acceleration multiplied by time. If i were to calculate how far an object will go, I would multiply the acceleration by one half and then multiply that by the square of time. To find the formulas of the data we collected, we simply plugged the data into excel. The x axis stood for the time while the y axis encompassed distance.  I noticed that the graph displaying our first experiment with the marble showed equal distance between each point on the scatter plot. This way, I could literally see what constant velocity looks like. The graph for the second experiment did not have the same distance between the points, however. The distance between the points slowly but gradually increased. I could tell that the increase was about the same amount between every set of points.

        To support our data, we found the equation of the line for each graph. We then converted these equations form numbers to words in order to understand why the numbers represented.  I made the observation, same as in the heart experiment, that if you plug in a time, then you can determine the future trend in the data. lastly, the three most important things that I took form this lab was that acceleration and velocity do not always correlate with each other. I also learned that the slope of an incline determines how the velocity and acceleration act. Thirdly, that if something is accelerating at a constant speed does not mean that there is a constant velocity.

Constant Velocity VS Constant Acceleration

Constant velocity means that the object travels in equal distance in equal time segments
                                        WHILE
Constant acceleration means that the object travels a distance that increases by the same amount at each interval.
 This video helped me understand the difference visually between the two and also put what I learned into my own words.

Hovercraft

Riding the hovercraft felt like you were floating. Some one who has never riding a hovercraft should expect to feel as if they were floating, as if one could keep floating forever if no one stops you. The feeling is different from riding a bike or skateboard because you can feel the friction of  the road and wheels. Inertia is what makes the start and stop of the hovercraft an effort.  Net force is the measurement of force needed to start or stop the hovercraft while equilibrium is the state in which the hovercraft is able to maintain a constant speed without any force.  The acceleration, however, cannot happen without velocity and force. Similarly, one would expect to achieve a constant velocity when  the hovercraft is floating- or in its state of equilibrium. Since  equilibrium is broken only when  an outside force intervenes; however some members were harder to stop and end this equilibrium than others.  The connection deals with mass. The higher the mass, the more force needed to stop the hovercraft.

example of inertia

 The ball is thrown at the goalley. The ball bounces on the ground and the boy ultimately catches it. This is an example of inertia. According to Newton's First Law: an object in motion tends to stay in motion, unless acted upon by an outside source. The ball's inertia, or state of motion would have stayed the same if there had not been the grass for friction and the boy to catch it and stop it.

This year, I expect to learn about how objects move and are affected by the properties of physics.
I expect to learn about gravity, velocity, and inertia. Physics can be found anywhere. It is applied in all areas of life and is important to understand because you can apply it to your personal understanding of the world around you. Physics can be a confusing subject, however. I am curious about the difference between speed and acceleration. I am also curious on how gravity affects the motion and speed of an object. Thirdly, I am curious as to what areas in life will surprise me when finding out that physics can be applied to them. In physics, I hope to achieve a reasonable grade as well as understanding and loving what I am learning. I also want to fully understand the curriculum at the end of the year and be able to explain certain concepts to someone random.