A bomb of mass 1 kg is thrown vertically upwards with a

A bomb of mass 1 kg is thrown vertically upwards with a speed of 100 m/s. After 5 seconds it explodes into two fragments. One fragment of mass 400 gm is found to go down with a speed of 25 m/s. What will happen to the second fragment just after the explosion? (g = 10 m/s²)

1. It will go upward with speed 40 m/s
2. It will go upward with speed 100 m/s
3. It will go upward with speed 60 m/s
4. It will also go downward with speed 40m/s

Speed of bomb after 5 second, v = u – gt = 100 –10 × 5 = 50m/s

Momentum of 400 g fragment =	400	× (-25) [downward]
	1000

Momentum of 600g fragment =	600	v
	1000

Momentum of bomb = 1 × 50 = 50
From conservation of momentum
Total momentum before splitting = total momentum after splitting.

⇒ 50 = -	400	× 25 +	600	v
	1000		1000

⇒ v = 100 m/s [upward]