A cannon and a supply of cannon balls are inside a sealed railroad car. The cannon fires to the right, the car recoiling to the left. The cannon
balls remain in the car after hitting the far wall. Show that no matter how the cannon
balls are fired the railroad car cannot travel more than its length L, assuming it starts
from rest. ·

Question

A cannon and a supply of cannon balls are inside a sealed railroad car. The cannon fires to the right, the car recoiling to the left. The cannon
balls remain in the car after hitting the far wall. Show that no matter how the cannon
balls are fired the railroad car cannot travel more than its length L, assuming it starts
from rest. ·

anonymous · Answer

I'm having trouble solving this problem. I'm unsure if its a center of mass problem or a Linear momentum one.

irishboy123 · Answer

yes this is a centre of mass problem

i'd start by looking at the position where the car does travel the full length L, and ask myself what that says about the canon balls......and everything else
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