Question 1: Velocity of a car increases uniformly at the rate of 5 ms-1 and after 10 s becomes 45 ms-1 . Find the acceleration of the car.
Solution
Here,
initial velociti u = 5ms-1
final velociti v = 45ms-1
time t = 5s
acceleration a = ?
We know,
a = (v – u)/t
or, a = (45 ms-1 -5 ms-1)/5s
= 40 ms-1 / 5s = 8 ms-2
Ans : 8 ms-2
Question 2: The Velocity of a car decreases uniformly from 20 ms-1 and after 4s it becomes 4 ms-1. Find the acceleration of the car.
Solution
Here,
initial velocity u = 20 ms-1
final velocity v = 4 ms-1
time t = 4 s
acceleration a = ?
We know,
a = (v – u)/t
or, a = (4 ms-1 – 20 ms-1)/4 s
= – 16 ms-1 / 4 s = – 4 ms-2
Ans : – 4 ms-2
