Question

A 1000kg car slows down from 30m/s to 20m/s. The change in kinetic energy will be.?​

Answer 1

Answer:

The work done is the same as the amount of energy increase. The formula for kinetic energy is 12mv2 .

The initial KE of the car is 12(1000)×202=200,000 joules.

The final KE of the car is 12(1000)×302=450,000 joules.

The difference between these is the amount of work done: 450,000−200,000=250,000 joules.

Answer 2

Answer:

250×10^3 joules

Explanation:

We know kinetic energy formula=

1/2(mass of body)(velocity of body)^2

So Intial kinetic energy(i)= 1/2(1000)(30)^2

final Kinetic energy(f)=1/2(1000)(20)^2

Change in Kinetic energy=450000 - 200000

=250000 joules

Thanking you