Question

A car travel with a velocity of 36 km/h. Its velocity changes after 4 seconds. Its final velocity become 54km/h . Calculate the acceleration of the car in m/s square

Answer 1

First of all Convert into SI unit.

=> 36 Km/h = (36 x 5/18) m/s = 10 m/s

=> 54 Km/h = (54 x 5/18) m/s = 15 m/s

Now,

Initial Velocity (u) = 10 m/s

Final Velocity (v) = 15 m/s

Time (t) = 4 s

Now as we know that,

=> v = u + at

=> 15 = 10 + a x 4

=> 15-10 = a x 4

=> 5/4 = a

=> a = 5/4 m/s^2

=> a = 1.25 m/s^2

Hence, the Acceleration attained by car = a = 1.25 m/s^2

Answer 2

Given,

Initial Velocity of Car (u) = 36 km/h = (36 x 5/18) m/s = 10 m/s

Final Velocity of Car (v) = 54 km/h = (54 x 5/18) m/s = 15 m/s

time (t) = 4 s

Now,

=> V = u + at

=> 15 = 10 + 4a

=> 15-10 = 4a

=> 4a = 5

=> a = 5/4

=> a = 1.25 ms^-1