Question

A bullet of mass $200\text{g}$ fired with a velocity of $200\text{m/s}$, hits a block of mass $2\text{kg}$ moving with a velocity of $10\text{m/s}$. After hitting the block, the bullet lodges into it. What is the velocity of the combined system? Assume that the collision is perfectly inelastic.

• A. $27.27\text{m/s}$
• B. $20\text{m/s}$
• C. $54.54\text{m/s}$
• D. $36.36\text{m/s}$

Answer 1

The correct option is A $27.27\text{m/s}$

Before collision

After collision

Applying conservation of linear momentum before and after collision.
$m_1{u}_1+m_2{u}_2=(m_1+m_2)v$
$0.200\times 200+2\times 10=(0.2+2)v$
$\Rightarrow v=27.27\text{m/s}$
Velocity of block after collision is $27.27\text{m/s}$
The correct option is (a).