Question

A stone is dropped from a certain height which can reach the ground in 5 second. If the stone is stopped after 3 second of its fall and then allowed to fall again, then the time taken by the stone to reach the ground for the remaining distance is

• A. 2 sec
• B. 3 sec
• C. 4 sec
• D. None of these

Answer 1

The correct option is C 4 sec

Total distance = $\frac{1}{2}g{t}^2=\frac{25}{2}g$
Distance moved in 3 sec ​= $\frac{9}{2}g$
Remaining distance = $\frac{16}{2}g$
If t is the time taken by the stone to reach the ground for the remaining distance then
$\Rightarrow \frac{16}{2}g=\frac{1}{2}g{t}^2\Rightarrow t=4sec$