Question

How much work would have to be done to bring a 1150kg automobile traveling at 86km/h to a stop?​

Answer 1

Explanation:

We have,

Mass of an automobile is 1150 kg

The automobile traveling at 86 km/h and then it comes to stop.

86 km/h = 23.88 m/s

It is required to find work done by the automobile.

Concept used : Work energy theorem

Th change in kinetic energy of an object is equal to the work done by it. The work done is then given by :

$W=\dfrac{1}{2}m(v^2-u^2)$

Here, v = 0

$W=-\dfrac{1}{2}mu^2\\\\W=-\dfrac{1}{2}\times 1150\times (23.88)^2\\\\W=-327896.28\ J$

or

$W=3.27\times 10^5\ J$

Therefore, the work done by the automobile is $-3.27\times 10^5\ J$.