The speed of a car travelling on a straight road

The speed of a car travelling on a straight road is listed below at successive intervals of 1 s:
Time (s)        0 1 2 3 4
Speed (m/s)  0 2 4 6 8

Which of the following is/are correct?

The car travels

  1. with a uniform acceleration of 2 m/s2.
  2. 16 m in 4 s.
  3. with an average speed of 4 m/s.

Select the correct answer using the code given below:

  1. 1, 2 and 3
  2. 2 and 3 only
  3. 1 and 2 only
  4. 1 only

Answer

Initial speed of car, u = 0

Final speed of car, v = 8 m/s

Time = 4 s

Acceleration = Change in velocity / Time interval

a = (v - u)/t

a = 8/4 = 2 m/s2 (Statement 1 is correct)

v2 - u2 = 2as

s = 64 - 4 = 60 m (Statement 2 is incorrect)

Average speed = 60/4 = 15 m/s (Statement 3 is incorrect)

The correct option is D.