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.