Question

How much work must be done in the car to slow it from 100km/h to 50km/h

Answer 1

`-96.465m` joule

Step-by-step explanation:

Let m = mass of the car and v1 = initial velocity and v2 = final velocity

Given.

Initial velocity = 100 km/h

final velocity = 50 km/h

What is work done in the car to slow it from 100km/h to 50km/h?

`v1=100km/h=27.78m/s`

`v2=50km/h=13.89m/s`

The work done in the car to slow it from v1 to v2.

w=Δk

`w=k2-k1`

`w= (1)/(2)m(v2)^(2)- (1)/(2)m(v1)^(2)`

`w=(1)/(2) m(v2-v1)^(2)`

`w=(1)/(2)* m(13.89 -27.78)^(2)`

`w=(1)/(2)* m(-13.89)^(2)`

`w=(1)/(2)* m* (-192.93)`

`w=-96.465m` joule.

Therefore, the work done is
`-96.465m` joule