Question

3. A car is travelling with a speed of 36km/h. the driver applies the brakes and retards the car uniformly. The car is stopped in 5s. Find (i) the retardation of the car(ii) Distance traveled before it is stopped after applying the brakes.

Answer 1

Answer:

$-2m/s^2;25m$

Step-by-step explanation:

Initial velocity, u  = 36 km/h = $36*\frac{5}{18}$ = 10 m/s

Final velocity, v = 0 m/s (It came to rest)

time take, t = 5 s

i) retardation, a = $\frac{v-u}{t} = \frac{0-10}{5} =-2 m/s^2$

ii)distance traveled, s

$= ut+\frac{1}{2} at^2 = (10)(5) + \frac{1}{2}*(-2)(5)^2 = 50-25=25m$