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Question
A body of mass 60 kg has the momentum 3000 kg m s-1. Calculate:
- the kinetic energy.
- the speed of the body.
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Solution
(i) Kinetic Energy K.E. = `1/2 mv^2`
= `1/2 xx 60 xx 50 xx 50`
= 75000 J
= `75/10 xx 10000 J`
= 7.5 × 104 J
(ii) Mass of body m = 60 kg
momentum p = mv
= 3000 kg ms-1
∴ 60 V = 3000
∴ V = `3000/60`
= 50 ms-1
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