First slide

Motion of centre of mass

Question

The 3 kg block is projected along the frictionless surface with a velocity of 2 m/s as shown in figure. What will be the velocity of 3 kg block when 6 kg block will be moving with same velocity as the centre of mass of the blocks.

Easy

A

$\frac{1}{4} m / s$
B

$\frac{3}{4} m / s$
C

$\frac{2}{3} m / s$
D

$\frac{1}{3} m / s$

Solution

$V_{C} = velocity of centre of mass = \frac{3 \times 2}{6 + 3} m / s = \frac{2}{3} m / s$
$\begin{array}{l} ∴ 6 \times \frac{2}{3} + 3 \times V = (6 + 3) \times V_{C} \\ \Rightarrow V = \frac{1}{3} [9 \times \frac{2}{3} - 6 \times \frac{2}{3}] \frac{m}{s} = \frac{2}{3} \frac{m}{s} \end{array}$

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