Question

A stone is projected vertically up from the bottom of a water tank. Assuming no water resistance it will go up & come down in same time but if water drag is present then the time it takes to go up, $t_{up}$ and the time it takes to come down, $t_{down}$ are related as

• A. $t_{up}>t_{down}$
• B. $t_{up}=t_{down}$
• C. $t_{up}<t_{down}$
• D. Can not say

Answer 1

The correct option is C $t_{up}<t_{down}$

While moving up & while moving down

$\because a_{up}>a_{down}$

Deceleration is more while going up than while coming down.

Hence to cover same distance $t_{up}<t_{down}$