Question

36. A car retards uniformly at the rate of 5 m/s2 and stops in 10 s. The initial velocity of car is (a) 10 m/s (b) 5 m/s (c)50 m/s (d) 25 m/s​

Answer 1

Answer:

Given: Final velocity, v=0 m/s , Retardation, a=−2.5 m/s

2

, Time, t=10s

Step 1 : Use first equation of motion

Let u be the initial velocity of the car.

As the acceleration is constant, so we can use equations of motion

v=u+at

⇒ 0=u+(−2.5)×10

∴ u=25m/s