# Finding the angle of the velocity vector of a projectile at moment of impact

1. Oct 19, 2014

### Corey333

1. The problem statement, all variables and given/known data
A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of 16.0 m/s. The cliff is h= 41.0 m above a flat horizontal beach
h=41
g=10m/s
vi=0m/s
vf2=vi2+2gh
vi=28.64
h=vi+vf/2xt
41=28.64/2xt
14.32
t=2.86
28.64x28.64, 16x16
Square root of 1076.24=32.806

I don't know how to find the angle, On my homework it requires the speed of which the impact lands which is 32.806, and the time it takes to strike the cliff after the stone is thrown which is 2.86, but it is asking for the angle below the horizontal but I don't know how to get it PLEASE HELP A.S.A.P.
I have a 90% on my homework right now but I need to find the angle to get a 100%, I'm a gpa freak I really need this help thank-you in advance!

2. Oct 19, 2014

### voko

I assume you mean the angle the velocity vector makes with the horizontal. Find the horizontal and vertical components of velocity, and, given that, find the angle.

3. Oct 19, 2014

### Corey333

I have that, 28.64 and 16, I just don't know what to do with that.

4. Oct 19, 2014

### voko

Draw a triangle, two sides of which are the components of the velocity vector. The hypotenuse in the triangle is the velocity. How are the angles and the sides in the triangle related?