A barrel (treated as a uniform cylinder, rotational inertia I = ½mr²) accelerates down the incline under gravity, resisted by rolling friction and air drag: a = g·sin(θ)/1.5 − (μ·g·cos(θ) + drag). At the bottom of the ramp it becomes a projectile, falls under gravity, bounces up to twice, then rolls along the flat ground decelerating under μ·g + drag until it stops.
- Steeper incline → higher launch speed off the ramp end
- Heavier barrel → drag matters less relative to its momentum
- Smooth steel has the lowest rolling friction — it travels farthest