Question

The energy required to accelerated a car from 10m/s to 20m/s is how many times the energy required to accelerate the car from rest to 10m/s

Answer 1

Energy required to accelerate from 10m/s to 20m/s is KE1 and KE2 is the energy required to accelerate from rest to 10m/s

KE1=
$\frac{1}{2} m {v}^{2} - \frac{1}{2} m {u}^{2} \\ \frac{1}{2} m( {20}^{2} - {10}^{2} ) \\ 150m$
KE2=
$\frac{1}{2} m {v}^{2} - \frac{1}{2} m {u}^{2} \\ \frac{1}{2} m( {v}^{2} - {u}^{2} ) \\ \frac{1}{2} m( {10}^{2} - 0) \\ \frac{1}{2} m100 = 50m$

KE1=150m
KE2=50m

so KE1=3KE2.

hence answer is 1/3 times energy required to make body accelerate from rest to 10m/s than from 10m/s to 20m/s.

Answer 2

Answer:

3 times

answer is given in the attachment