Hi, I have been having a lot of trouble with this problem. I have been trying to figure it out for hours with limited success... Any help would be very much appreciated!(adsbygoogle = window.adsbygoogle || []).push({});

1. The problem statement, all variables and given/known data

A football is thrown toward a receiver with an initial speed of 16.9m/s at an angle of 38.6 degrees above the horizontal. At that instant, the receiver is 17.4m from the quarterback. The acceleration of gravity is 8.81m/s2. With what constant speed should the receiver run to catch the football at the level at which it was thrown? Answer in units of m/s.

2. Relevant equations

V0cosθ= Vy

V0sinθ= Vx

1. Range= (V0^2 sin2 θ)

------------

g

2. displacement X= Vxt

3. delta X= V0t + 1/2 at^2

3. The attempt at a solution

I drew a picture, and because the problem says it is caught on the same level, I assumed I could use the range formula. So I did that and found the total Range (delta X). Then, I plugged that into the 2nd equation to find the total time the football is in the air.

I took the answer I got from the Range formula (delta X) and subtracted 17.4m from it because that is how far the receiver will have to run. Then, I used the 2nd equation again to find how long it took the football to travel 17.4 meters. I took that time and subtracted it from the total time to find out how much time the receiver would have to run and catch the football. Then, I used the Delta X/ that time to get the Vx. Are my steps right? Because when I tried to submit the answer online, it said my answer was incorrect...

When I did all these steps, I got an answer of 13.20769597 m/s.

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# Homework Help: 2-D motion: projectile motion of football

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