a 1811kg car speeds up from rest when a traffic light turns green until it reaches a speed of 23m/s. how much work was done on the car by friction?

The work done by the frictional force, W = 612565.32 J

Explanation:

Given data,

The mass of the car, m = 1811 kg

The initial velocity of the car, u = 0 m/s

The final velocity of the car, v = 23 m/s

Let the time period of the car be, t = 3 s

The acceleration of the car,

a = (v-u) / t

= (23 - 0) / 3

= 7.67 m/s²

The normal force acting on the car,

F = mg

= 1811 kg x 9.8 m/s²

= 17747.8 N

The displacement of the car,

s = ut + ½ at²

= 0 + ½ x 7.67 x 3²

= 54.52 m

The work done by the frictional force,

W = F · S

W = 17747.8 N x 54.52 m

= 612565.32 J

Hence, the work done by the frictional force, W = 612565.32 J