Question

A body of mass 1 kg initially at rest, explodes and breaks in to three fragments masses in the ratio 1:1:3 the two pieces of equal mass fly off perpendicular to each other,with speed of 15 m/s each . the speed of the heavier fragment is

• A. $5\sqrt{2}m{s}^{-1}$
• B. $45m{s}^{-1}$
• C. $10m{s}^{-1}$
• D. $15m{s}^{-1}$

Answer 1

The correct option is C $10m{s}^{-1}$

Given,

$u=0$

$m=1kg$

According to law of conservation of linear momentum.

$M_1{V}_1=mv+mv+3V_m$

$V=15m/s$

$15kg\ast 0=15m+15m+3xm$

assumming masses $m,m$ and $3m$ and.

$x=$ velocity of heavier fragment

$0=30m+3xm$

or, $x=-\frac{30}{3}=-10m/s$.