Question

If a car of mass 500kg change its velocity from 40m/s to 60m/s. What would we work done for the change​

Answer 1

answer:5,00,000 Joules

Answer 2

Explanation:

As we know that change in kinetic energy is equal to work done by system

so in first case when it's velocity is 40 km/h calculate it's kinetic energy

don't forget to change speed unit

i.e. K.E.=1/2×500×(40×5/18)^2

and in 2nd case when velocity is 60km/h

than its kinetic energy

K.E.=1/2×500×(60×5/18)^2

hence Work done=change in k.E.

w=1/2×500×[(60×5/18)^2-(40×5/18)^2]

W=250×(5/18)^2×[(60^2)-(40^2)]

W= 38.58 KJ