Question

An object is dropped from a platform100 ft high. Ignoring wind resistance, how long will it take to reach the ground?

Answer 1

0  = -16t^2 + 100    subtract 100 from each side

-100  = -16t^2     divide both sides by -16

100/16   = t^2       take the positive root of both sides

10/4  = t   =  2.5 seconds

Hope this helps :)

Answer 2

Answer:

Time taken 2.49 s

Explanation:

Given

Initial Velocity u = 0 m/s

Height H = 100 ft

Solution

Using equation of motion

$H = ut + \frac{1}{2}gt^2\\\\100 = 0 + 0.5 \times 32.2 \times t^2\\\\t= 2.49 second$