# Frames of reference, trajectory

1. Jun 1, 2013

### James9118

I'm hoping you can help with a debate I'm having with a friend regarding whether throwing a ball in a headwind is the same or different from throwing a ball from a moving platform (lets say an open boat).

If you want some numbers, could you please work with these:

For the static throw, can we imagine the wind is blowing at 20m/s and the throw is made at 30m/s vertically. Cd of ball = 0.5, mass of ball = 0.1kg, diam of ball = 0.1m.

For the boat, this is travelling at 20m/s in still air. Same throw, same ball.

So is the trajectory, as viewed by the thrower in each case, different or the same?

Many thanks, James

2. Jun 1, 2013

### Staff: Mentor

Physics is the same in all inertial frames. You just have to find appropriate inertial frames to apply this concept.

3. Jun 1, 2013

### Simon Bridge

Welcome to PF;
What mfb said...
Since the object is to be convincing as well as correct, I'd do both cases from the POV of someone standing on the bank and then translate to the throwers POV.
That should help.