Speed of a body in motion is doubled. Its kinetic energy is now …………. Times the original kinetic energy.

Options

A. two
B. three
C. four
D. half

Explanation

kinetic energy `E_(k)=(1)/(2)mv^(2)`
Now, doubling its speed,
`E_(k).=(1)/(2)m(2v)^(2)`
`=(1)/(2)mv^(2)xx4=4E_(k)`
Thus, the kinetic energy of the object becomes four times.