Question

In what distance can a 1,500 kg automobile be stopped if the brake is applied when the speed is 20 m/s and the coefficient of sliding friction is 0.7 between the tires and the ground?

a) 40 m
b) 60 m
c) 80 m
d) 100 m

Answer 1

The car can be stopped in approximately 142.86 meters.

Step-by-step explanation:

To calculate the distance needed to stop a car, we can use the equation:

d = (v^2) / (2 * u)

Where d is the distance, v is the initial speed, and u is the coefficient of sliding friction. In this case, the initial speed is 20 m/s and the coefficient of sliding friction is 0.7. Plugging these values into the equation, we get:

d = (20^2) / (2 * 0.7) = 200/1.4 = 142.86 m

Therefore, the car can be stopped in approximately 142.86 meters.