The kinetic energy of an object of mass ‘m’ moving with a velocity of 5 m s-1 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?
We know that,
Kinetic energy = 
mv2
25 = 
× m × (5) 2
25 = 
× m × 25
m = 
= 2 kg
In the first case, the velocity of 5 m/s is doubled
So the velocity becomes 5×2 = 10 m/s
Kinetic energy = 
mv2
= 
× 2 × (10) 2
= 
× 2 × 100
= 100 J
Therefore, when the velocity is doubled, then its kinetic energy becomes 100 J
In the second case, the velocity of 5 m/s is increased three times.
So the velocity becomes 5×3 = 15 m/s
Kinetic energy = 
mv2
= 
× 2 × (15) 2
= 
× 2 × 225
= 225 J
Therefore, when the velocity of object is increases three times, then its kinetic energy becomes 225 J