# What is the Kinetic energy of an object moving at the speed of light?

As the material body travels at the speed of light its relativistic
mass becomes infinite. Hence the kinetic energy too becomes
infinite which is not practically possible

The kinetic energy of an object is calculated using the following formula:

KE = 1/2 m(v^2)

Where:

m = mass of the object

v = velocity of the object

If the object is moving at the speed of light, then v = 3x10^8 m/s^2

Without a given mass for the object, the kinetic energy of the object cannot be calculated. If a mass (in Kg) is known, then it is simply plugged into the formula. For example, let's say that the object has a mass of 100kg. Then the formula would be:

KE = 1/2 (100kg)(3x10^8 m/s^2)^2

KE = 1/2 (100Kg)(9x10^16 m/s^2)

KE = 4.5x10^18 J

KE = 4.5x10^18 J

If the object has any mass before it starts moving, then its mass and kinetic energy

at the speed of light are both infinite.

at the speed of light are both infinite.