Projectile Motion: Football Thrown at Moving Receiver

[coffeeandativ]

Homework Statement

A football player throws a football at a player who is 10m away. The football is fired at 20m/s at 30degrees above the horizontal. If the receiver is running straight away from the quarterback at
12.25m/s will he catch the football (assuming the ball is caught at the same height as it is thrown from)?

Homework Equations

vix=vcostheta
viy= vsinthetha
range= vi^2(sinthetha)^2 divided by the acceleration
vf=vi+at
delta x= vit+1/2at^2

The Attempt at a Solution

Using the equations I wrote above this is what I managed to solve so far.
vix=17.32ms
viy= 10ms
to find the time I used vf=vi+at and I got 2.04s which I substituted into the delta x equation to get a total of 61m.

I'm not sure if I'm on the right track to solving this problem or not, any help would be great. Thank you!

 

[gneill]

It's not clear how you've used the equations that you give to find the values that you state. Perhaps you could lay out your calculations in a bit more detail?

 

[Andrew Mason]

What is the condition (in terms of the physics) that must apply in order for their to be a catch?

AM