Question

Starting from rest, a car accelerates uniformly for 2 seconds, then moves at constant velocity 12 m/s for 3 seconds, and then decelerates uniformly for 3 seconds until it comes to rest. If the total distance (in metres) covered by the car is 10X, the value of X is

Answer 1

Answer:

6

Given Final Velocity v=0, deceleration a=4ms−2 and deceleration time t=3s,

Let u be the velocity before the deceleration is started.

Using v=u+at   ⇒0=u−4×3  ⇒u=12,ms−1, 

Now , During acceleration, Initial velocity u1=0, time t=2s, Final velocity u=12ms−1, 

Let acceleration is a. 

Using v=u+at  ⇒12=0+a×2  ⇒a=6ms−2