# Help solving inital velocity

1. Feb 19, 2005

### runner1738

A man can throw a ball a maximum horizontal distance of 136 m on a level field. The acceleration of gravity is 9.8 m/s^2. How far can he throw the same ball vertically upward from the ground? (Assume that the ball is thrown from the ground and that his muscles give the ball the same speed in each case.) Answer in units of m.

My work: I was trying to use the range equation to solve for vi so 136=v^2sin(2theta)/g ok so 136x9.8= 1332.8=v^2sin(2theta) , im obviously missing something what is it? thanks

2. Feb 19, 2005

### Staff: Mentor

What is the angle $\theta$ for maximum range? Assume no air resistance.

When you obtain the velocity, then apply it to the vertical case.

3. Feb 19, 2005

### runner1738

45 degrees and sin(45) is sqrt(2)/2 so really its 1332.8=v^2(sqrt(2)) , which for v i got 30.69905402 thank you, i didnt think of that