Question
Tue December 04, 2012 By:

The kinetic energy of an object of mass m,moving with a velocity of 5m/s is 25 J.What will be its kinetic energy when its velocity is doubled?What will be its kinetic energy when its velocity is increased three times?

Expert Reply
Thu December 06, 2012

the K.E(KINETIC ENERGY) of the object is 25 J.

So,

25=1/2*m*(5)2

Therefore,m=2 kg.

Now, when the velocity is doubled, velocity becomes=2*5=10 m/s(ms-1)

So,

K.E.=1/2*2*(10)=100 J.

Now,when the velocity is increased three times,the velocity will be=3*5=15m/s

Therefore,K.E.=1/2*2*(15)2 = 225 J.

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