Question

A turnip is dropped from a height of 70 meters. How long does it take to hit the ground?

Answer 1

Here's a formula for the distance an object falls from rest:

D = (1/2) A T² ... <== MEMORIZE THIS

Distance = (1/2) · (acceleration) · (time²)

On Earth, the acceleration of gravity is always 9.8 m/s².  So for a fall that starts with zero speed, the formula says

70 m = (1/2) (9.8 m/s²) (time²)

70 m = (4.9 m/s²) (time²)

Divide each side by  (4.9 m/s²) ;

time² = (70 m) / (4.9 m/s²)

time² = (70/4.9) sec²

time = √(70/4.9)  seconds

time = 3.78 seconds