Question

A body strikes the floor vertically with a velocity $u$ and rebounds at the same speed. The change in speed would be

• A. $u$
• B. $3u$
• C. $2u$
• D. Zero

Answer 1

The correct option is D Zero

The speed of the particle after rebounding is also $u$ but in opposite direction to that of initial speed. Thus only the direction of the velocity changes but its magnitude remains the same. So, the change in magnitude of velocity (i.e. speed) is zero.