Question

How much work is required to make a 1400 kg car increase its speed from 10 m/s to 20 m/s?​

Answer 1

7000J

Step-by-step explanation:

Given parameters:

Mass of car = 1400kg

Initial speed = 10m/s

Final speed = 20m/s

Unknown:

Amount of work done = ?

Solution:

In this problem, the amount of work done is the same as the change in kinetic energy of the body.

So;

Work done = Final kinetic energy - initial kinetic energy

Kinetic energy =
`(1)/(2)` m v²

Work done =
`(1)/(2)` m(V²f - V²i )

m is the mass

vf is the final velocity

vi is the initial velocity

Work done =
`(1)/(2)` x 1400 x (20 - 10) = 7000J