Question

The kinetic energy of an object of mass M is moving with a velocity 5 metre per second is 25 joules. What will be its kinetic energy when its velocity is increased 3 times

Answer 1

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)2 =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.

Answer 2

The kinetic energy of an object is 25 joules.  

so to find out the value of mass (m)

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)

then,

kinetic energy=K E=1/2*2*(10)2 =100 joules

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

K.E.=1/2*2*(15)2 = 225 J.