- #1
k_squared
- 64
- 0
Homework Statement
A soccer ball is kicked. If there is a 3 meter high fence, that is 6 meters away, compute the angle of the kick and the magnitude of the velocity of a ball.
Homework Equations
a_y=-g
v_y=-gt+v_y_0
s_y=-(1/2)gt^2+v_y_0(t)
v_x is constant: we neglect air resistance.
6=v_x_0t
3. The Attempt at a Solution
Because the maximum height is 3, the direction of v_y changes from positive to negative at this point.
0= -gt+v_y_0
3=-.5gt^2+t*v_y_0
We solve this system of equations to yield the initial speed in the y direction, and the time at which the ball passes over the fence. We then use the equations for the position on the x axis: 6=tv_0_x and compute V_0_x.
We use arc-tangent to get the angle from the two speeds. The angle is wrong. My maximum speed is close, but still wrong.
What is the problem with this set of equations such that it will not yield a correct answer?