Calculate Max Angle of Deflection for Ball on Cord

[bob7]

Homework Statement

A ball with a mass, m1=0.24 kg, initially moves to the right with a speed of 5m/s. The first ball then has an elastic collision with a second ball with a mass of .56kg which is initially at rest. The second ball is suspended just above the table by a cord which is 1.5 meters long. Right after the collision occurs, m2 moves to the right with a speed of 3m/s.

How would I go about calculating the maximum angle of deflection (measured from the vertical) that a ball attached to a cord will achieve?

Homework Equations

In the first part of the question I had to find the mass of the second ball and the final velocity of the first ball. m2=.56kg and Final Velocity of m1 is -2m/s

The Attempt at a Solution

 

[Dick]

If you know the initial speed of m2, you know it's initial kinetic energy. When it reaches to the top of it's swing all of that will be converted to potential energy. How high does it go? Now use that to find the angle.

 

[bob7]

now i found the height to be .46 meters. the length of the cord is 1.5 meters. And I need to find the angle in between the initial position (from it just hanging) to the final position (when it is in the air). Now that creates a triangle, but I can't figure out how to get at that angle. Thanks for all the help!

 

[Dick]

You get at the angle by figuring out some sides and using trigonometry. What's the vertical side? What's the hypotenuse?