Question

A bomb of mass 9kg explodes into 2 pieces of mass 3kg and 6kg. The velocity of mass 3kg is 1.6m/s, the K.E. of mass 6kg is

• A. 3.84 j
• B. 9.6 j
• C. 1.92 j
• D. 2.92 j

Answer 1

The correct option is C 1.92 j

Given,

$M=9kg$

$m_1=3kg$

$m_2=6kg$

$v_1=1.6m/s$

$v_2=?$

By the conservation of linear momentum,

$Mv=m_1{v}_1+m_2{v}_2$

$0=3\times 1.6+6\times v_2$

$v_2=0.8m/s$

The kinetic energy of $m_2$ particle,

$K=\frac{1}{2}{m}_2{v}_2^2\hat{j}$

$K=\frac{1}{2}\times 6\times 0.8\times 0.8\hat{j}$

$K=1.92\hat{j}$

The correct option is C.