A bomb of mass 1kg is thrown vertically upwards with a speed of `100ms^(-1)`. After 5 seconds, it explodes into two fragments. One fragment of mass 400grams is found to go down with a speed of `25ms^(-1)`. What will happen to the second fragment just after the explosion? (Take `g=10ms^(-2)`)

Options

A. it will go upward with speed `100ms^(-1)`
B. it will go upwards with speed `40ms^(-1)`
C. it will go upward with speed `60ms^(-1)`
D. it will go downwards with speed `40ms^(-1)`

Answer

A

Explanation

`v= u-g t= 50 ms^(-1)`, This is the velocity at the time of explosion
According to the principle of conservation of linear momentum,
`1 xx 50 =(400)/(1000) xx (-25) + (600)/(1000) xx v rArr v= 100ms^(-1)`