Journal 12/4

We also know that if we study the motion of any object that is freely falling near the surface of the earth we find that it moves with an acceleration of 9.8 m/s/s (if its interaction with the air is small enough to ignore.)

Make a new post on your blog titled "Journal 12/4" and address the following questions:

1. Write a mathematical expression for the force that the earth exerts on an object of mass m. Remember that when an object is falling freely Fnet = Fearth on obj

Fnet= mass (9.8 m/s/s)

2. Your friend Abe says "If you drop a marble and a bowling ball from the top of the school, being careful to let go of them both at the same time, they will both hit the ground at the same instant. This means the force of the earth is the same on both objects." Do you agree with Abe? Why or why not? If you disagree, how would you try to convince him using a real-world example that he could try himself?

Here's the thing, the force is not the same. The equation to find the earth's Force is mass x 9.8 m/s/s. So the bowling ball has a greater force pull than the marble because the marble has less mass. A feather and a pair of glasses have two different masses so their forces would not be the same.

3. Your friend Ben says "If I duct-tape two bricks together the earth pulls on them twice as hard as a single brick. Therefore, the double brick will fall twice as fast." Do you agree with Ben? Why or why not? If you disagree, how would you try to convince him using a real-world example that he could try himself?

Ben's right, the mass is increased by two, so the force will be twice as much as if it was just one. Therefore the mass will be greater and it will fall faster.