# Football kick

1. A football is kicked at an angle of 45 degrees from a distance of 37 meters and just clears a 3 meter high goal on its way down. To the nearest m/s what was its initial speed?

2. v = v_0 + a*t
v^2 = (v_0)^2 + 2a*(x - x_0)
x=x_0 + (v_0)t + (1/2)*a*t^2

3. I set the original velocity as V and tried to solve but I got a negative number

## Answers and Replies

Delphi51
Homework Helper
Separate the initial velocity v into horizontal and vertical parts. Then write two headings:
Horizontal and Vertical. Decide in each case whether you have constant speed or accelerated motion and write the appropriate formula(s). Your x = formula is not correct. You don't have a y = formula. Put in the numbers or expressions for all known quantities and try to make progress on all three fronts.

rl.bhat
Homework Helper
First of find the vertical and horizontal components of v_o.
Displacement is given, . Find time t in terms of v_ox.
In the last equastion
y = y_o + v_oy*t - 1/2*g*t^2, substitute the value of t and solve for v_o.