A car travels with a uniform velocity of 25m/s for 5s.The brakes are then applied and the car is uniformly retarded and comes to rest in further 10s.Find (i)the distance which the car travels before the brakes are applied (ii)the retardation and (iii) the distance travelled by the car after applying the brakes.

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Answers

2016-02-05T18:37:45+05:30
Initial velocity u=0, final velocity v=25m/s,  time=5s
So by applying the formuls :  v=u+at ;  a=v-u/t;  25-0/5= 5m/s²
(1) distance which the car travels before the brakes are applied=  S=ut+1/2at²=62.5m   
(2)the retardation=-acceleration=5m/s²
(3) the distance travelled by the car after applying the brakes=250m.
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