Ball thrown vertically in air question?

[yamaha277]

Homework Statement

a) A 2.0 kg ball is thrown vertically in the air with an inital velocity of 10.0 m/s. What is the height of the ball when the velocity is 5.0 m/s?

b) A 2.0 kg ball is thrown vertically in the air. The height of the ball when the velocity is 5.0 m/s is 6.07 m. What is the initial velocity of the ball?

Homework Equations

The Attempt at a Solution

the max height reached by a) is 5.10 m

I know how to find the max height reached by the ball with the initial velocity but can't figure out how to find the height at certain velocities.

Please help!

 

[mgb_phys]

Do you know "v^2 = u^2 + 2as" ?

 

[yamaha277]

This?
(square of final velocity) = (square of initial velocity) + 2*acceleration* distance

Would your final velocity in a) be 5.0 m/s therefore solving for s?
If that is correct, i get 3.83 m

 

[mgb_phys]

There are three standard equations of motion (see the sticky at the top of this thread)
You need to know them - and which to use depending which factors you know.

 

[yamaha277]

I have those and got:

A) 3.83 m
B) 11.99 m/s

Does the seem right?