Projectile motion football kick problem

AI Thread Summary
The discussion revolves around solving a projectile motion problem involving a football kick to score a field goal. The kicker can launch the ball at an initial speed of 25 m/s from a distance of 50 m, with the goalpost height set at 3.44 m. Participants discuss the equations of motion, specifically how to relate the horizontal and vertical components of the kick to find the angles of elevation. There is confusion regarding the variables used in the equations, particularly the distinction between initial speed (Vo) and other terms. The conversation emphasizes the need to correctly manipulate the projectile motion equations to determine the required angles for a successful kick.
Cherrybawls
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Homework Statement


A football kicker can give the ball an initial speed of 25 m/s. what are the least and greatest angles of elevation at which he can kick the ball to score a field goal from a point 50m in front of the goalposts whose horizontal bar is 3.44m above the ground?


Homework Equations


I really don't know what to do


The Attempt at a Solution


I figured I could write
V0tcosX=50
and
V0tsinX-.5gt2=3.44

Then I tried to find t in terms of X and got
t=50/(V0cosX)

Then I plugged that into the other equation and I got
50tanX-12250/cos2X-2150=0

I thought then I could find the zeros and that would be my answer but it doesn't seem to be working... I can't figure out why. Maybe I totally missed the answer but either way I still need help lol. Thanks.
 
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you can write the equation of the projectile as
y = x*tanθ - (g/2*u^2)*x^2*sec^2(θ)
Put sec^2(θ) = 1 + tan^2(θ) and solve the quadratic for tanθ.
 
I am confused, what are you referring to with u?
 
Sorry. u is Vo.
 
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