The collision of two balls of equal mass takes place at the origin of coordinates. Before collision, the components of velocities are (`v_(x) = 50cm^(-1)` , `v_(y) = 0`) and `(v_(x) = -40cm^(-1)` and `v_(y) = 30cms^(-1)`. The first ball comes to rest after collision. The velocity (components `v_(x)` and `v_(y)` respectively) of the second ball are

Options

A. 10 and `30 cms^(-1)`
B. 30 and `10 cms^(-1)`
C. 5 and `15 cms^(-1)`
D. 15 and `5 cms^(-1)`

Answer

A

Explanation

x-direction `mxx550-mxx40=mxx0+mv_(x)`
`implies v_(x)=10 cm//s`
y-direction, `mxx0=mxx30=mxx0+mv_(y) implies v_(y)=30 cm//s`