An 1120 kg car traveling at 17.2 m/s is brought to a stop while skidding 40m. Calculate the work done on the car by the friction forces.

Work = 165670.4 J = 165.67 KJ

Explanation:

First, we will find the deceleration of the car, using the 3rd equation of motion:

where,

a = deceleration = ?

s = skid distance = 40 m

vf = final speed = 0 m/s

vi = initial speed = 17.2 m/s

Therefore,

the negative sign indicates deceleration here.

Now, we will calculate the braking force applied by the brakes on the car:

the negative sign indicates braking force.

Now, we will calculate the work done using the magnitude of this force:

Work = 165670.4 J = 165.67 KJ