Question

A car starts from rest with a constant acceleration 2.3 m/2 for 16 second. Then the car decelerates uniformly at 3 m/2 and finally it stop.

i) Sketch a graph of velocity (v) against time(t) for the journey

ii) Calculate the velocity for the car

iii) Calculate the time taken when it uniformly decelerates

Answer 1

Answer:

Let v,t

1

,t

2

be the maximum velocity attained, time for which car accelerated and the time for which car retarded respectively

⇒t

1

=(v−u)/a=(v−0)/2=v/2

⇒t

2

=(v−u)/a=(0−v)/(−4)=v/4

Now it is given that,

⇒t

1

+t

2

=3

⇒v/2+v/4=3

⇒v=4m/s

Hence correct answer is option C

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