Question

The brakes of a certain car can produce an acceleration of 6 m/s2. (a) How long does it take the car to come to a stop from a velocity of 30 m/s? (b) How far the car travel during the time the brakes are applied?

Answer 1

Answer:

(a) 5 s

(b) 75 m

Explanation:

(a) u = 30 m/s

v = 0 m/s

a = -6 m/s²

As v = u + at,

0 = 30 + (-6) (t)

-6t = -30

t = 5 s

(b) As 2as = v² - u²,

(2) (-6) (s) = (0)² - (30)²

-12s = -900

s = 75 m