A woman drops a rock from a bridge to the water 17.5 m below. with what speed does the rock strike the water? a. 0 m/s b. 18.5 m/s c. 171m/s d. 9.8 m/s e. 17.5 m/s

Question

asked Aug 23, 2021 145k views

1 Answer

Jimmy Sanchez · Answer 1 · 2021-08-26T20:08:28+0000

Given :

Height from which rock is dropped, h = 17.5 m.

Initial velocity, u = 0 m/s.

To Find :

Speed does the rock strike the water.

Solution :

We know, by equation of motion :

v^2-u^2=2as ......( 1 )

Here , a = g = 9.8 m/s² ( Acceleration due to gravity )

Putting all given values in 1 , we get :

$v^2-u^2=2as\\\\v=√(2gh)\\\\v=√(2* 9.8* 17.5)\ m/s\\\\v=18.5\ m/s$

Therefore, speed with rock strike the water is 18.5 m/s.

Hence, this is the required solution.