Imagine,a pond with 100m depth,from the bottom an iron ball is projected.It reached 80m up and when it's about to come down all the water vanished suddenly. Will its final velocity(while coming down)be more than its initial velocity(while going up)?

While going up water reduced its velocity, now there is no water to stop it.

1 Answer
Mar 24, 2018

Lower velocity

Explanation:

All we need to think about is energy. The ball starts with just kinetic energy and as it rises through the water, it loses that energy primarily from drag.

Therefore the object has less energy and when it lands it will have a lower velocity.

The fact that the ball goes to 80 m is completely irrelevant. We don't really have actual numbers for the speed because we aren't doing fluid dynamics, but we know it's lower.