# I'm confused by this concept 2-d motion dumb question

## Homework Statement

A cart that is rolling at constant velocity on a level table fires a ball straight up. When the ball comes back down, will it land in front of the launching tube, behind the launching tube, or directly in the tube? Explain.

## The Attempt at a Solution

Why does it land right back into the cart. That is super counterintuitive for me. I feel like the only forces on it if we don't include air friction is gravity. Therefore shouldn't it land behind the cart?

phinds
Gold Member

## Homework Statement

A cart that is rolling at constant velocity on a level table fires a ball straight up. When the ball comes back down, will it land in front of the launching tube, behind the launching tube, or directly in the tube? Explain.

## The Attempt at a Solution

Why does it land right back into the cart. That is super counterintuitive for me. I feel like the only forces on it if we don't include air friction is gravity. Therefore shouldn't it land behind the cart?
Suppose you are standing in the aisle of an airplane that is moving at 600mph and you jump up a couple of feet in the air. Where do you think you would come down? Why?

Bystander and billy_joule
Suppose you are standing in the aisle of an airplane that is moving at 600mph and you jump up a couple of feet in the air. Where do you think you would come down? Why?
In the same place. O this is without air friction right

CWatters
Homework Helper
Gold Member
The problem statement does not say if you should or shouldn't ignore air resistance. I would give answers for both cases.

kuruman
Homework Helper
Gold Member
In phinds' plane example, the air moves with the plane and there is no horizontal motion relative to the air to affect the landing spot when someone jumps straight up. In the demonstration below, there is horizontal motion relative to the air but the ball still lands in the cart. Therefore, air resistance can be safely ignored because the experiment says so.

phinds