High School

A 2200 kg car traveling at 28 m/s slams on the brakes and skids to a halt. What is the force exerted by the brakes to bring the car to a stop?

Answer :

Answer:

In this case, the force exerted by the brakes to bring the car to a stop is 15092 Newtons.

Explanation:

To calculate the force exerted by the brakes to bring the car to a stop, we can use the concept of kinetic friction. When the car is skidding to a stop, the force of kinetic friction between the tires and the road is what slows down the car.

1. First, calculate the kinetic friction force using the formula:

[tex]\( f_k = \mu_k \times N \)[/tex]

where [tex]\( \mu_k \)[/tex] is the coefficient of kinetic friction and [tex]\( N \)[/tex] is the normal force acting on the car.

2. Next, find the normal force acting on the car:

[tex]\( N = m \times g \)[/tex]

where [tex]\( m \)[/tex] is the mass of the car (2200 kg) and [tex]\( g \)[/tex] is the acceleration due to gravity (9.8 m/s²).

3. Calculate the normal force:

[tex]\( N = 2200 kg \times 9.8 m/s^2 = 21560 N \)[/tex]

4. Determine the coefficient of kinetic friction, which depends on the surfaces in contact. Let's assume a value of [tex]\( \mu_k = 0.7 \)[/tex] for this scenario.

5. Now, substitute the values into the first formula to find the kinetic friction force:

[tex]\( f_k = 0.7 \times 21560 N = 15092 N \)[/tex]

6. Therefore, the force exerted by the brakes to bring the car to a stop is 15092 Newtons. This force is in the opposite direction of the car's motion and is what causes it to decelerate and eventually come to a halt.