9. Force is required to change an object velocity.Force is equal to mass times acceleration.
10. Force acting on object are paired with equal and opposite forces
Step-by-step explanation:
9.
Newton's 2nd law states that force is a product of mass and acceleration.In this case, the force of friction is causing deceleration of the ball.This is an example of rolling friction.Acceleration of the ball depends directly on this friction but indirectly on its mass.
10.
From Newton's 3rd Law ,for every action there is an equal and opposite reaction.The astronaut throwing the ball will experience the effect of an external force againts his own which is equal and in the opposite direction to the force she applied.This is why the astronaut moves backward but slower.
