Question

When the speed of the body is doubled what is the change in its kinetic energy?

• A. Kinetic energy becomes double to its initial kinetic energy.
• B. Kinetic energy becomes four times to initial kinetic energy.
• C. Kinetic energy becomes triple to its initial kinetic energy.
• D. Kinetic energy can not be determined.

Answer 1

The correct option is B Kinetic energy becomes four times to initial kinetic energy.

We know, kinetic energy = $\frac{1}{2}$ m $v^2$
Kinetic energy is proportional to the square of the velocity.
If the velocity is doubled, kinetic energy becomes four times to initial kinetic energy.