Question

3.A car accelerates from rest to a speed of 54 km/h in 20 seconds. What is the acceleration of the car in m/s2?

Answer 1

Answer:

Acceleration = ∆v/t

initial velocity = 0m/s

final velocity = 54km/h = 15m/s

time = 20 sec

A = 15 - 0/20op

15/20

3/4

= 0.75ms-²

Answer 2

Answer:

Explanation:

Given :-

Initial speed of car, u = 0 (As starts from rest)

Final speed of car, v = 54 km/h = 54 × 5/18 = 15 m/s

Time taken by car, t = 20 seconds

To Find :-

Acceleration, a = ?

Formula to be used :-

1st equation of motion,

i.e v = u + at

Solution :-

Putting all the values, we get

v = u + at

⇒ 15 = 0 + a × 20

⇒ 15 = 20a

⇒ 15/20 = a

⇒ a = 0.75 m/s²

Hence, the acceleration of the car is 0.75 m/s².