# 10. Class 11th Physics | MOD | Solved Example-6 on Uniform Acceleration | by Ashish Arora

In this example we are given that a car is

moving at twenty meters-per-second. The driver applies the brakes. which causes a retardation

of. Four meter-per-second square. Find the distance traveled by the car before it stops,

if reaction time of driver is point-four second. The very first thing is the you must know

about the reaction time. Reaction time , you can simply define as the time. Taken by a

human. To execute. The action. After one seas , and need of it. In our case if we talk about

the driver, when he seas the need to apply the brakes on If it’s reaction time is point

four second that mans. after point four second he will push the paddle of brakes. So till

point four second car will move with the uniform speed and then the retardation will be apply

to the car. say if this is the car, which moving at a velocity of twenty meters per

second, We can say at t=zero he seas the need to apply the breaks on. So we can say

up to point four second the car will travel at the same speed of . twenty meters-per second.

If t=point four second it will move with the same velocity and then, the retardation

will be applied i.e. four meter-per-second square. And due to this now the car will be

retarded, and finally the car will come to, rest after some time, by covering some distance.

In this situation if we find out the first part , when, the driver’s reaction time

was going on. The distance traveled , s-one can be written as, this velocity multiplied

by the time, as it was moving at a uniform speed, so it is simply eight meter. If We

find out the second part of this journey. That is, the retardant motion of the application

of breaks, this distance s-two can be calculated by using the speed equation v-f-square=u-square

+ two” a”-s. here final velocity is zero. Initial velocity was twenty, acceleration

was minus four as it is retarded, we can write minus. Eight, s-two the distance we have taken

as s-two, so in this situation, the second displacement s-two can be simply given as

four-hundred by eight. And it is fifty meter. So this s-two=fifty meter, so answer to the

question is . we are require to find the total distance covered by the car, i.e. s-one +

s-two it will be . eight + fifty this is, fifty-eight meter this will be the answer

to this question .

## 6 Replies to “10. Class 11th Physics | MOD | Solved Example-6 on Uniform Acceleration | by Ashish Arora”

Sir Is Physics Galaxy making a video on Analysis of Jee advance 2017?????

nice videos sir

where r u from??

the quality of video is quite low , everything was looking blurr

Happy guru purnima sir

hello I am studying in allen jaipur .sir, I want to ask a question. In physics I am facing many problem regarding question understanding and its language. So please sir suggest me what I do.please sir reply me.