How Do You Calculate the Speed and Maximum Height of a Stone Thrown Upward?

[pyromonkey39]

Homework Statement

A stone is thrown vertically upward. On its way up it passes point A with speed v and point B 3.0 m higher than point A.With speed (1/2)*v Calculate a. the speed v b. the maximum height reached by the stone above point B.

Homework Equations

v = v₀ + at

The Attempt at a Solution

I wrote down all the information given and then drew a picture but I am not entirely sure where to start. I assumed that acceleration would be -9.8 m/s due to gravity but if i don't know time how can I calculate what is being asked.

 

[Dougggggg]

Have you been given a formula something to this degree?

y = y₀ + v₀t + \frac{1}{2}at²

 

[pyromonkey39]

that was in the chapter but my professor has not gone over it in class yet so I am not sure on how to go about using it

 

[Dougggggg]

If your professor is not giving you the proper instruction. Try watching lectures online to stay caught up before you fall behind and have no idea what is going on. Check out open course ware at mit.edu, they have many many video lectures. The Physics I guy is a genius and a great teacher.

As for your problem, here is the best advice I can offer you. Try to think about the things you know. You know that at a point y=3.0 m (if you define point A as y=0), there is a velocity that is half the starting velocity.

If you set it up right, you should have 2 equations with 2 unknowns. Use some algebra skills and you should find some useful information.