- #1
mauritzhansen
- 4
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Hi folks,
Need some help on a projectile motion question.
Given:
- a football kicker can give the ball an initial speed of 25m/s
- kicker wants to score a field goal 50m in front of goalposts
- horizontal bar of goalposts is 3.44m above the ground
Question:
What are the a.) least and b.) greatest elevation angles at which he can kick the ball to score a field goal?
none
I have done the following:
1.) y = y0 + (v0sinθ)t - 0.5(9.81)t2
so, 3.44 = (25sinθ)t - 4.91t2
2.) x = x0 + (v0cosθ)t
so, 50 = (25cosθ)t
so, t = 2/cosθ
I then substituted eq. 2 into eq. 1, and got the following:
3.44 = 50tanθ - 19.62sec2θ
but I am stuck here.
Could someone please tell me if I am on the right track? Is there a way to solve the above equation, or am I approaching this in the wrong way?
Thanks.
Need some help on a projectile motion question.
Homework Statement
Given:
- a football kicker can give the ball an initial speed of 25m/s
- kicker wants to score a field goal 50m in front of goalposts
- horizontal bar of goalposts is 3.44m above the ground
Question:
What are the a.) least and b.) greatest elevation angles at which he can kick the ball to score a field goal?
Homework Equations
none
The Attempt at a Solution
I have done the following:
1.) y = y0 + (v0sinθ)t - 0.5(9.81)t2
so, 3.44 = (25sinθ)t - 4.91t2
2.) x = x0 + (v0cosθ)t
so, 50 = (25cosθ)t
so, t = 2/cosθ
I then substituted eq. 2 into eq. 1, and got the following:
3.44 = 50tanθ - 19.62sec2θ
but I am stuck here.
Could someone please tell me if I am on the right track? Is there a way to solve the above equation, or am I approaching this in the wrong way?
Thanks.