The speed of a particle is doubled, its kinetic energy:

Kinetic energy KE of a body of mass m moving with velocity or speed v is given by the formula:

KE = m v2


so kinetic energy is directly proportional to the mass of object and to the square of speed of the body.


If the speed of particle is doubled then kinetic energy becomes four time.


KE1 = mv12


KE2 = mv22 where, v2 =v1


Substituting the value of v2 in the formula,


KE2 = m (2v1)2


= (4 mv12)


KE2 = 4 KE1


So kinetic energy will become 4 times if the speed is doubled.

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