Question

A Car Travelling at a speed 54km/hr is brought to rest in 90s.find the distance travelled by the car before coming to rest. ​

Answer 1

Answer:

take u as 0 ... then use the formula... it's really easy..

Answer 2

Answer:

A Car Travelling at a speed of 54km/h is brought to rest in the 90s. The distance traveled by car before coming to rest is $672.3m$

Explanation:

We have equations of motions to find the distance traveled by a body when velocity and time are given, that is

the distance $s=ut+\frac{1}{2}at^{2}$

where $u$-initial velocity

           $t$-time taken

           $a$-the acceleration of the body

from the question, it is given that

the initial speed of the car $u=0$

the time taken to bring to rest $t=90s$

acceleration is the change in the velocity with respect to time

here $a=v/t$

the velocity of the body $v=54km/h=54*5/18=15m/s$

⇒$a=15/90=0.16m/s^{2}$

substitute these values to get distance

$s=\frac{1}{2}*0.166*90^{2}=672.3m$