 # The magnitude of kinetic energy of a body is ‘k’. what is its kinetic energy if its velocity is doubled ?

Kinetic energy is transferred between objects and can be transformed into other forms of energy. Kinetic energy is given by

KE =1/2mv2

where KE is the kinetic energy, m is the mass of the body

v is the velocity of the body

Units of Kinetic Energy

• The SI unit of kinetic energy is Joule which is equal to 1 kg.m2.s-2.
• The CGS unit of kinetic energy is erg.

Examples

• A truck travelling down the road has more kinetic energy than a car travelling at the same speed because the truck’s mass is much more than the car’s.
• A river flowing at a certain speed comprises kinetic energy as water has a certain velocity and mass.

When speed doubles kinetic energy becomes

The change in the kinetic energy of the object as the speed changes is proportional to the square of the factor by which the speed changes. If the speed of the object becomes double, its kinetic energy changes to four times the initial kinetic energy.

If v becomes 2v, then

KE = ½m(2v)2

= 4—½mv2

= 4 times initial KE

Check out the video given below to know more about kinetic energy and potential energy Articles to explore (40) (12)