Question

A grenade having mass of 10 kg flying horizontally with a velocity of 10 m/s explodes into two fragments. The larger fragment has a velocity 25 m/s in the
direction of the initial velocity of the grenade. The smaller fragment has a velocity of 12.5 m/s in the opposite direction. The masses of the fragments are....
(1) 2 kg, 8 kg
(2) 3 kg, 7 kg
(3) 4 kg, 6 kg
(4) 4.5 kg, 5.5 kg

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Answer 1

ans : option (3).....by using law of conservation of momentum

Answer 2

Answer:

Option C is correct

Explanation:

As the grenade explode automatically so there is no external force acting on it.

As no external force acting on it we can conserve momentum here.

Initial momentum of grenade = 100

let assume the mass of bigger fragment is x, so mass of smaller fragment will be (10-x).

now final momentum = 25(x) - 12.5(10-x)

so by conservation of momentum

Initial momentum = Final momentum

We get the value of x = 6 kg (mass of bigger fragment)

so the mass of smaller fragment = 10 - 6 = 4 kg