Question

At six flags there is a ride called the gunslinger. On this ride you sit in a swing and the ride spins you in a circle so that the rides move outward radially and upward vertically. What force causes the swings to move upward vertically?

I think the upward lift is caused by the changing direction of inertia, but this is just a guess. Can someone confirm or correct this?

Answer 1

It's more just basic principles of circular motion. Gravity is pretty much counteracted entirely in this case.

As the ride spins, there will be a centripetal force acting inwards which will accelerate the swings towards the center of the ride (the force being provided by the cable between the ride and the swing).

You might still ask, "okay, well if it's moving towards the middle of the ride, why do the swings move outward?"

The answer lies in the equation for centripetal acceleration:\[a_{c} = \frac{ v^{2} }{ r }\]For simplicity. let's assume 'a' remains constant. If the ride begins and starts increasing the 'v' of the swings, then that will require 'r' to get larger. Hence, the swings move further from the center of the ride.

I'm not certain how the rides operate, but i'm assuming they just have a specific tension that the cables of the swings can withstand, and they just won't exceed such a tension. Which means 'a' probably will go up a little bit since the increase in 'v' would not be fully compensated by 'r' in that case.

As to why the swing moves upwards:
The cable attached to the swing is a specific length. If the swing moves out, basic trigonometry will show you that it has to move up. No force is acting in the vertical direction. Gravity acts with force 'mg', but the swing counteracts all of that as a normal force equal to 'mg' in the opposite direction.

In summary. Centripetal force keeps the swing in circular motion. Swing moves outward due to the velocity of the swing increasing by the circular motion equation. Swing moves upwards due to the unchanging cable length.

Hope that explains it well enough!