Question

Brakes applied to a car produce a uniform retardation of 90 cm/
$m {s}^{2}$
if the car was travelling with a velocity of 27 m/s then what is the distance will it covers before coming to rest?

Answer 1

Use equation of motion S = v² - u² / (2a)

S = (0² - (27 m/s)²) / (2 × -90 m/s²)
= 4.05 m

4.05 m of distance is covered by car before coming to rest

Answer 2

In this question
u=27m/s
v=0
a =-90

so By using 3rd equation of motion
$2as = {v}^{2} - {u}^{2}$
2×-90=0-729
1 80s=729
s=729/180
s=4.05m