Question

A woman leaning over the railing of a tall bridge accidentally drops her cell phone. If the bridge is 31.16 m high, how long will it take the phone to hit the river below the bridge?

Answer 1

Answer:

2.52 s

Explanation:

We can use equation of motion to solve this.

$s \: = ut + \frac{1}{2} a {t}^{2}$

Assuming initial velocity to be 0 and no air resistance,

$s \: = \frac{1}{2} a {t}^{2} \\ 31.16 = \frac{1}{2} (9.81) {t}^{2} \\ t = 2.52s$

Answer 2

2.52 (: is correct . have a good day