A rock is dropped from a cliff that is 45 m high. How long does it take to hit the ground?
Physics · High School · Tue Nov 03 2020
Answered on
Given:
Rock dropped from a cliff that is 45 m high.
Determine How long does it take to hit the ground.
The formula for Falling Objects
D = ½ gt^2
D = 45 m
g = (9.8m/s^2)
Solution:
Substitute the given height of the rock to the equation for the formula for falling objects.
D = ½ gt^2
45 m = ½ (9.8 m/s^2) t^2
45 m = 4.9 m/s^2 t^2
Divide both sides by 4.9 m/s^2.
45 m/ 4.9m/s^2 = 4.9 m/s^2 t^2/4.9m/s^2
t^2 = 9.18 s^2
Take the square root of both sides in order to determine the time.
√t^2=√9.18s^2
t = 3.03 s
Final answer:
It would take 3.03 seconds for the rock to hit the ground.