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 :
[tex]v^2-u^2=2as[/tex] ......( 1 )
Here , a = g = 9.8 m/s² ( Acceleration due to gravity )
Putting all given values in 1 , we get :
[tex]v^2-u^2=2as\\\\v=\sqrt{2gh}\\\\v=\sqrt{2\times 9.8\times 17.5}\ m/s\\\\v=18.5\ m/s[/tex]
Therefore, speed with rock strike the water is 18.5 m/s.
Hence, this is the required solution.