MCQ
A $40\ g$ ball dropped from a certain height bounces back from the horizontal ground without losing mechanical energy. If its speed is $10\ m/s$ just before making contact with the ground, and the average value of the force of the ground on the ball is equal to $16\ N$ while ball and wall are in contact, how long were they in contact .......... $m/s$
- A$25$
- ✓$50$
- C$75$
- D$100$
