A car is accelerated on a levelled road and attains a speed of 4 times its initial speed. In this process, the kinetic energy of the car:
(a) does not change
(b) becomes 4 times that of initial kinetic energy
(c) becomes 8 times that of initial kinetic energy
(d) becomes 16 times that of initial kinetic energy

As known the expression for the Kinetic energy $K=\frac{1}{2}mv^2$

Here $m\rightarrow$ mass

$v\rightarrow$ velocity

If the car attains a speed of 4 times its initial speed then it becomes $4v$

Then kinetic energy of the car $K'=\frac{1}{2}m(4v)^2$

Or $K'=16(\frac{1}{2}mv^2)$

Or $K'=16K$

So, the kinetic energy of the car becomes 16 times that of the initial kinetic energy.

Therefore, option (d) is correct.

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Updated on: 10-Oct-2022

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