A particle of mass m moving towards west with speed v collides with another particle of mass m movies towards south. If two particles st ich t o each other the speed of the new particle of mass 2 m will be

Options

A. v
B. `v//2`
C. `v/(sqrt2)`
D. `vsqrt(2)`

Answer

C

Explanation

Let `W - E` is x-axis `S - N` is Y - axis & `bar(v)` be final velocity vector.
`implies 2 m barv = m v hat I + m v hatj implies barv = v/2 (hati + hatj)`
`implies |barv| = v/(sqrt2)`