Question

A car moving along a straight highway with speed of 126 km/ h to brought to stop within a distance of 200 m. what is the retardation of the car and how long does it take for the car to stop? subject:

Answer 1

u=126km/h initial velocity
v=0
s=0.2km
a=?

now use formula v^2-u^2=2as
0-15786=2a(0.2)

a=39690km/h^2
change unit according to asked.

Answer 2

given that u=126km/h

v=0

s=0.2km

so 2as=v^2-u^2

a=v^2-u^2/2s

a=39690