# Homework Help: What am i doing wrong? Angle of vector?

1. Oct 12, 2011

### nc1617

1. The problem statement, all variables and given/known data

A ball is tossed so that it bounces off the ground, rises to a height of 3.10 m, and then hits the ground again 0.70 m away from the first bounce.

2. Relevant equations
H= .5(v^2/g) for y velocity.

3. The attempt at a solution
Vy=squareroot of(60.822) Vy= 7.799 m/s
Vx= .70 m/1.59 s= .441 m/s
inversetangent(Vy+Vx)= angle ------ is this correct?

i did the inversetangent and it came out to be about 79.4 degrees. but that wasn't the correct answer :(

2. Oct 12, 2011

### issacnewton

your Vx , Vy are correct but the angle is wrong.

$$\tan(\theta)=\frac{V_y}{V_x}=\frac{7.79}{0.44}$$

3. Oct 12, 2011

### nc1617

thank you! :)