First slide

Second law

Question

A wagon of 200 kg is moving on a smooth track with velocity of 2 m/sec. A man of 80 kg also runs in the wagon with a velocity such that speed of the centre of mass of the system is zero. Find the velocity of man relative to the wagon (in m/s).

Moderate

A

5
B

6
C

7
D

8

Solution

Velocity of centre of mass
$v_{com} = \frac{m_{wagon} \times v_{wagon} + m_{man} \times v_{man}}{(m_{wagon} \times m_{man})}$
$v_{com} = \frac{(200) (2) + (80) (V)}{280} = 0 \Rightarrow V = - 5 m / s$
$\vec{v_{man}} = {\vec{v}}_{man, wagon} + \vec{v_{wagon}}$
${\vec{v}}_{man, wagon} = {\vec{v}}_{man} - {\vec{v}}_{wagon} = - 5 - 2 = - 7 m / s$

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