Two bodies having equal masses are moving with uniform speeds of v and 2v respectively. Find the ratio of their kinetic energies.

Let the masses of the two bodies (m1) and (m2) be m kg

Let the velocity of the first body be v m/s


And the velocity of the second body be 2v m/s


Ratio of K.E = (KE) of body 1/ KE of body 2


= (1/2 mv2)/ (1/2 m (2v)2)


= v2/ (2v)2 = (1)2/ (2)2


= 1:4 (K.Ev2)


Hence, the ratio of their kinetic energies is 1:4


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