Question

34. A car starts from rest and accelerates uniformly at a rate of 2 ms-1 for 20 second. It then
maintains a constant velocity for 10 second. The brakes are then applied and the car is

uniformly retarded and comes to rest in 5 second. Find the distance travelled. Ans 900
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Answer 1

Explanation:

Accelerating at a rate of 2m/s for 20 seconds

So v at 20 secs is 2*20=40m/s

A= v-u/t = 40-0/20 = 2

In uniform acceleration,

S=ut+1/2at^2 = 0*10 +1/2(2)*20*20= 400m

In constant velocity, v=u=40

S =vt = 40*10=400m

Retardation ,here initial velocity will be final velocity of previous case

So, U=40, v=0, t=5s

A= 0-40/5 = - 8

S= 40*5 +1/2(-8)5*5 = 200-100 =100m

Total distance is 400+400+100 =900m

Answer 2

Answer:

the answer is attached below. Hope you Understand.