A car is moving on a straight road with a speed of 20 m/s At t = 0 ,the - Science - Motion

Question

A car is moving on a straight road with a speed of 20 m/s At t =
0 ,the driver of car applies the brakes after watching and obstacle
150 m ahead After application of brakes ,the car retards with
2m/s2 Find the position of car from the obstacle at t =
15 sec

Jyoti Pant · Accepted Answer

Here initial velocity u=20m/s,Final velocity v=0,Acceleration a= $- 2 m / s^{2}$

Now,To calculate the time taken by car to stop

v=u+at

0=20+(-2)t

t=10sec

Car will stop in 10 seconds,it means after 15 sec car would have the same position as at the end of 10 seconds.

The distance travelled by the car in 10 seconds

$s = u t + \frac{1}{2} a t^{2} s = 20 \times 10 + \frac{1}{2} \times (- 2) \times 10^{2} = 100 m$

The position of car from the obstacle=150-100=50m.

A car is moving on a straight road with a speed of 20 m/s .At t = 0 ,the driver of car applies the brakes after watching and obstacle 150 m ahead .After application of brakes ,the car retards with 2m/s2 .Find the position of car from the obstacle at t = 15 sec

A car is moving on a straight road with a speed of 20 m/s .At t = 0 ,the driver of car applies the brakes after watching and obstacle 150 m ahead .After application of brakes ,the car retards with 2m/s² .Find the position of car from the obstacle at t = 15 sec