First slide

Rectilinear Motion

Question

A stone is dropped from a certain height which can reach the ground in 5 s. It is stopped after 3 s of its fall and then it is again released. The total time taken by the stone to reach the ground will be

Moderate

A

6s
B

6.5s
C

7s
D

7.5s

Solution

$\begin{array}{l} Here h = \frac{1}{2} \times 10 \times (5)^{2} = 125 m \\ In 3 s it falls through: h_{1} = \frac{1}{2} \times 10 \times (3)^{2} = 45 m \\ Rest 80 m is covered in 4 s . Hence, total time taken is \\ 3 s + 4 s = 7 s \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App