What is the Y-Component of a Baseball's Acceleration at Half Its Terminal Speed?

[pedro_infante]

Homework Statement

A baseball is thrown straight up. The drag force is proportional to v^2.
In terms of g , what is the y-component of the ball's acceleration when its speed is half its terminal speed and it is moving up? moving back down?

Homework Equations

F=ma
mg+bv^2=ma
mg-Bv^2=ma

The Attempt at a Solution

been trying to start it but I just don't see how.

 

[Soveraign]

What is the acceleration "a" when the object is at terminal velocity?

Using your equations, what is the terminal velocity in terms of m, g, and b?

Now, what is "a" when you cut "v" in half?