A 1200 kg car is travelling qt 20m\s determine the work that must be done on the car by the frictional force of the brakes to stop the car

240000 Joules

Explanation:

Applying,

The work that must be done by the frictional force of the brake to stop the car must be equal to the kinetic energy of the car.

W = mv²/2 Equation 1

Where W = work done by the frictional force of the brake, m = mass of the car, v = velocity of the car.

From the question,

Given: m = 1200 kg, v = 20 m/s

Substitute these values into equation 1

W = (1200×20²)/2

W = 240000 Joules

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.