Question

A car that runs 40 kilometers per hour, puts a brake and stops it in 2 meters, if the speed of the car is 80 kilometers per hour, then how many distance will it stop

Answer 1

In the first scenario,

u= 40km/hr
S=2m= 0.002km.
v=0 ( As the vehicle comes to rest)

Using the Formula
${v}^{2} = {u}^{2} + 2as$
${0}^{2} = {4 0 }^{2} + 2a(.002)$
2a= -1600/0.002
a= -400000 km/hr^2


using this 'a' solving for the second scenario,

u=80 km/hr
v=0

0= 80^2 - 2(400000)S
S= 6400/800000
S= 8 meters.


Hope this helps.