A body of mass 5 kg moves along X-axis with `2ms^(-1)` A second body of mass 10 kg moves along y-axis with velocity `sqrt3 ms^(-1)`. They collide at the origin and stick together. The velocity of the combined mass is :

Options

A. `3/4ms^(-1)`
B. `4/3ms^(-1)`
C. `3/8ms^(-1)`
D. `8/3ms^(-1)`

Answer

b

Explanation

Here Momentum of first body before collision
`|vec(p1)|=10 kg ms^(-1)`
Momentum of second `|vec(p2)|=10sqrt3 kg ms^(-1)`
Resultant momentum
`|vecp|=sqrt((10)^2+3xx10^2)=20 kg m^(-1)`
Applying Law of Conservation of momentum
`(5+10)v=20`
or `v=(20)/(15)=4/3ms^(-1)`.