Within a substance, atoms that collide frequently and move independently of one another are most likely in a.

it looks like u already answered q11.

q12. the line on the speed time graph would be moving up and down.

q13. the object would accelerate a slower because of the same force being applied to a heavier object.

rolling a small 1 pound ball(ball a) vs rolling a 10 pound ball(ball b) with the same force. ball a would move much more quickly because the amount of weight of the object is lower.

q14. newton's law stats "For every action, there is an equal and opposite reaction." so the wall would then push back the same amount