An orange drops to the ground from the top of a tree 45m tall. How long does it take to reach the ground?

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

QUESTIONS 40. An orange drops to the ground from the top of a tree 45m tall. How long does it take to reach the ground? 

WAEC1991 Ans: 3s

SOLUTIONS 

Acceleration due to gravity g, = 10m/s²

Height h, = 45m

Initial velocity u = 0m/s

Final velocity v, = ?

Time taken to fall t, =?

Therefore using h = ut + ½gt²

45 = 0(t) + ½(10)t²

45 = 0 + ½ 10t²

45 = 5t²

t² = 45/5

t² = 9

t =√9

t = 3s