Question

Your foot brake must be able to stop your car within __________ when it is travelling at 20 mph.

Answer 1

Your foot brake must be able to stop car within 5.18 m

Step-by-step explanation:

`d = s^(2)  / (250 * c_(f) )`

d is breaking distance.

s is speed in km/h

`c_(f)` is coefficient of friction normally 0.8

250 is constant.

Give the speed in mile first convert it to km/h

`1 km = 1.60934 mile`

speed in km= 20 * 1.60934

s =32.186 km/h

`d=32.186^(2)  / (250 * 0.8)`

d= 5.18m