Question

body of mass 1kg initially at rest explodes into 3 fragments in the ratio 1:1:3.the 2 pieces of equal masses fly off perpendiclr to each other with speed 30m/s each ..what is velocity of heavier fragment

Answer 1

let m is the mass of body initially at rest
after explosion three part form by this e.g m/5 , m/5 , 3m/5

now use law of conservation of momentum. because Fext=0

initial momentum = final momentum
m x 0 = m/5 (30 i) + m/5(30 j ) +2m/5 v

0 = 6i + 6j +2/5 v

v = -(6i + 6j )x 5/2
= -(15i + 15j)

hence , velocity of havier part = -(15i +15j)

magnitude of velocity = 15√2 m/s