Question

Find the mass of a body which has 5J of kinetic energy while moving at speed of 20 m/s

Answer 1

KE=1/2mv^2
5J=1/2m x 20 x 20
5J=1/2m x 400
5J=200m
m=5/200
m=0.025kg

Answer 2

The kinetic energy  E=1/2mv2 

So 5=1/2m⋅2^2

5=2m

∴m=2.5kg

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