Question

A car is moving in a straight line with speed 18 km per hour. It is stopped in 5 seconds by applying the brakes.Find the speed of the car after 2 seconds of applying the brakes in metre per seconds. ​

Answer 1

A car is moving in a straight line with speed 18 km/h.It is stopped in 5 s by applying the brakes.find: :.iii)the speed of the car after 2 s of applying the brakes.

Ask for details Follow Report by Singhsumita40 18.04.2015

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Initial speed, u=18km/h=5m/s

t=5s

final speed, v=0km/h

velocity of car t seconds after applying the breaks is given by

v(t)=u+at

plugin the given values above and find a :

0=5+a(5)\implies a=-1m/s^2

therefore the velocity of car as a function of time is

v(t)=5-t

plugin t=2 for the velocity of car 2 seconds after applying breaks:

v(t)=5-2=3m/s=10.8km/h