Question

A bomb at rest explodes into a large number of tiny fragments. The total momentum of all the fragments
(aj is zero
(b) Depends on the total mass of all the fragm
@ Depends on the speeds of various fragments
(d) Is infinity​

Answer 1

Answer:

Is Zero

Explanation:

According to the law of conservation of momentum

m1u1+m2u2=m1v1+m2v2

m1 and m2 are equal for both

and u1=u2=v1=v2

since, whole scenario is starring nd ending at rest

I.e u1=u2=v1=v2=0

0+0=0+0

0.

Answer 2

A bomb at rest explodes into a large number of tiny fragments.

The total momentum of all the fragments -

1. (a) is zero
2. (b) depends on the total mass of all the fragments
3. (c) depends on the speed of various fragments
4. (d) is infinity.

Concept : Law of conservation of linear momentum, “when there is no external force acting on a system of masses. linear momentum of system must be conserved.”

in short,

initial linear momentum = final linear momentum ...(1)

Let the mass of a bomb is M is at rest. at a moment, it explodes into a large number of tiny fragments of masses m₁ , m₂ , m₃ , m₄ ... all these fragments have velocities v₁ , v₂ , v₃ , v₄ ...

initial velocity of bomb , u = 0 [ ∵ bomb is at rest ]

∴ initial linear momentum = Mu = 0

now, final linear momentum = sum of momentum of all tiny fragments formed after explosion of bomb

= m₁v₁ + m₂v₂ + m₃v₃ + m₄v₄ + ...

from equation (1),

0 = m₁v₁ + m₂v₂ + m₃v₃ + m₄v₄ + ...

Therefore the sum of momentum of all the fragments is zero. hence option (a) is correct choice.