Question

i) Define momentum of body. On what factor does the momentum of a body depends?
ii) Calculate the change in momentum of a body weighing 5 kg when its velocity decreases from 20 m/s to 0.2m/s.
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Answer 1

Momentum is defined as mass x velocity. The momentum depends on the mass and the velocity of the body.

The change in momentum of a body =

weight = 5kg

u = 20 m/s

v = 0.2 m/s

mu = 5 x 20 = 100 kgm/s

mv = 5 x 0.2 = 10 kgm/s

change in momentum = 100 - 10 = 90 kgm/s

Answer 2

1. Momentum is the physical quantity which is the measure of the quantity of motion of a moving body. It depends on mass and velocity of the body.
2. we know that

change in momentum = final momentum – initial momentum

so,

change in momentum = mv- mu

or

= 5×0.2 – 5×20

or

= 1 – 100

thus,

Δp = – 99 kg.m/s2