Projectile Motion, Shooting a Ball in Zero Gravity.

[laxstud120]

Projectile Motion, Shooting a Ball in Zero Gravity. URGENT!

So I had to come up with my own problem for class, but this is going to be in zero gravity. I chose lacrosse.

Homework Statement

Chris Fiore does a split dodge with the help of a pick and gets his hands free for a sidearm shot from 15 yards. He is so good that when he shoots, the ball always travels in a 2D path! The initial velocity of the shot is 96mi/h (Chris Fiore is one of the fastest shooters in lacrosse). How long does it take until it hits the goal?

Homework Equations

Conversions:
15yd (0.91m) = 13.72m
96mi/h(1609.34m)(3600s) = 5.56x10⁸m/s

d = v_it + 1/2gt²

The Attempt at a Solution

If this is how it is calculated on Earth...
d = v_it + 1/2gt²
13.72 = (5.56x108)t + 0.5(-9.81) t²
-4.91t² + 5.56x108x -13.72 = 0
t = 2.47s

What the hell happens if the gravity is zero? I can't just put in 0 instead of -9.81 can I? From what I recall the whole formula doesn't even work if its not on earth! The ball would go insanely fast! Need some clarification on this. How would I go about calculating this? Thanks!

 

[fatra2]

Hi there,

Without the gravity field, you object will not fall. It will simply travel at constant velocity (neglecting the air friction) until it hits the goal!

 

[Matterwave]

Are you sure about that 5.56x10^8m/s speed of the ball? This Chris Fiore guy must have one hell of an arm to be able to shoot that ball faster than the speed of light!