Question

27. If a moving car increases its speed
from 30 km/hr to 60 km/hr, what will
be the impact of its kinetic energy?
(A) will become 2 times
(B) will become 4 times
(C) will become 6 times
(D) No change
​

Answer 1

Answer:(A)will become 2 times

Explanation:kinetic energy is the energy in a object b'coz of its motion.When the speed will increase by 2 times naturally the impact of its kinetic energy will be 2 times.

Answer 2

The kinetic energy "option (B) will become 4 times".

Explanation:

Let the mass of kinetic energy = $m_{1}$ = $m_{2}$ = m

Given,

$v_{1} =30\frac{km}{hr}$ and$v_{2} =60\frac{km}{hr}$

We know that,

The kinetic energy (KE) = $\dfrac{1}{2}mv^{2}$

The kinetic energy $(KE)_{1} = \dfrac{1}{2}m(30)^{2}=\dfrac{1}{2}m(900)$

The kinetic energy $(KE)_{2} = \dfrac{1}{2}m(60)^{2}=\dfrac{1}{2}m(3600)$

=$4[\dfrac{1}{2}m(900)]$

= 4 × $(KE)_{1}$

Thus, the kinetic energy "option (B) will become 4 times".