Question

while jeff was replacing the obstruction of light on a cell tower, he accidentally dropped his cell phone. If he was 150 ft up at the time, approximately how long did it take the phone to reach the ground

Answer 1

Answer:

3.19 seconds

Step-by-step explanation:

Given:

Phone gets dropped from a Height = 150 ft

To find:

Time taken for the phone to reach the ground = ?

Solution:

First of all, let us learn about the formula of distance in terms of Initial speed u; Time t and Acceleration a:

$s=ut+\dfrac{1}{2}at^2$

Here the phone is dropped from a height so a = g m/$s^2$ i.e. acceleration due to gravity.

g = 9.8 m/$s^2$

s = 150 ft

Initial velocity, u = 0

Putting all the values in the formula:

$150=0 t+\dfrac{1}{2}gt^2\\\Rightarrow 50=\dfrac{1}{2}\times 9.8 \times t^2\\\Rightarrow t^2=\dfrac{50}{4.9 }\\\Rightarrow t^2=10.20\\\Rightarrow t = 3.19\ sec$

So, the time taken is 3.19 seconds.