A body starts from rest and accelerates uniformly at 5m/s². Calculate the time taken by the body to cover a distance of 1 km.

John Perolski
August 07, 2023

Physics Jamb, Waec, Neco Past Questions & Answers on Speed, Velocity and Acceleration


QUESTIONS 13. A body starts from rest and accelerates uniformly at 5m/s². Calculate the time taken by the body to cover a distance of 1 km. 

WAEC 2005 Ans: 20 secs


SOLUTIONS


Initial velocity u = 0m/s

Acceleration a = 5m/s²

Time taken t = ?

Distance s = 1km = 1 x 1000 = 1000m


Applying the second equation of motion


S = ut + ½ at²

1000 = 0 x t + ½ x 5 x t²

1000 = 0 + 5t²/2

1000 = 5t²/2

Cross multiplying

1000 x 2 = 5t²

2000 = 5t²

t² = 2000/5

t² = 400

t = √400

t = 20 secs Answer