Answer:
45 m
Explanation:
From the question,
The kinetic Energy of the car = Work done by the brake that is needed to stop the car.
1/2mv² = F×d......................... Equation 1
Where m = mass of the car, v = velocity of the car, F = braking force of the car, d = distance the car travels before it comes to rest.
make d the subject of the equation
d = 1/2mv²/F.......................... Equation 2
Given: m = 2000 kg, v = 30 m/s, F = 20000 N
Substitute into equation 2
d = 1/2(2000)(30²)/20000
d = 1000(30²)/20000
d = 900000/20000
d = 45 m.
Hence the car travels 45 m before it comes to rest
