First slide

Location of centre on mass for multiple point masses

Question

In a free space, a rifle of mass M shoots a bullet of mass m at a stationary block of mass M at a distance D away from it. When the bullet has moved through a distance d towards the block, the centre of mass of the bullet-block system is at a distance of

Moderate

A

$\frac{(D - d) m}{M + m} from the bullet$
B

$\frac{md + MD}{M + m} from the block$
C

$\frac{2 md + MD}{M + m} from the block$
D

$\frac{(D - d) M}{M + m} from the bullet$

Solution

Distance between bullet and block at this instant is $(D - d)$ .
Distance of CM from bullet
$= \frac{M (D - d) + m \times 0}{M + m} = \frac{M}{M + m} (D - d)$
Similarly, distance of CM from block $= \frac{m}{M + m} (D - d)$
Hence, option (4) is correct.

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