[填空题]
1. A ball of mass $0.20\,kg$ moving on a frictionless horizontal plane collides elastically with a vertical wall.
The variation of the force F acting on the ball during the collision with time t is shown on the graph below.
The speed of the ball just before the impact is $5.0\,ms^{−1}$. Calculate the maximum force exerted on the wall by the ball. $F_{Max}$ = $N$
2.The wall is covered with a coating that causes an inelastic collision. The ball hits the wall with the same initial speed and bounces back with a speed of $3.0\,ms^{−1}$.
(1)Explain, by considering the moments just before and after the collision, how the principle of conservation of energy applies to the collision.
(2)Calculate the loss of the energy of the ball during the collision. $\Delta E_K$ = $J$
(3)During this collision, the ball undergoes a change in momentum. Determine whether the the law of conservation of momentum to the system of the ball and the wall.
