Acube of mass m1=7.6 kg is sitting on top of a second cube of the same size and mass m2=1.3 kg while both are in free fall. ignoring any air resistance, what is the magnitude of the normal force with which the bottom cube is acting on the top cube?

Zero

Explanation:

To solve the problem, we just need to analyze the forces acting on the top cube.

There are two forces acting on it:

- The force of gravity (the weight of the cube), downward, which is

where

is the mass of the cube

is the acceleration of gravity

- The normal reaction exerted by the bottom cube on the top cube, upward, which we indicate with R

So, the equation of the forces for the top cube is

where

is the acceleration of the cube, since it is in free fall

Solving for R, we find:

this means that the temperature of both substances will be equal

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.