A mass of 1 kg is thrown up with a velocity of 100 m/s. After 5 seconds. It explodes into two parts. One parts of mass 400 g comes down with a velocity 25 m/s Calaculate the velocity of other parts:

Options

A. 40 m/s upward
B. 40 m/s downward
C. 100 m/s upward
D. 60 m/s downward

Answer

C

Explanation

Velocity after 5 second
`V = 100 - 10 xx 6`
V = 50 m/s
From conservation of momentum
`1 xx 50 hat(j) = .04 xx 25 (-hat(j)) + 0.6 vec(v)`
`50 hat(j) + 10 hat(j) = 0.6 vec(v)`
`vec(v) (60 hat(j))/(0.6) = 100 hat(j) = 100 m//s hat(j)`