Virtual reality, video screen shots and sensor data for a large drop tower ride


Vertical drop towers enhance the skyline of a park and offer riders spectacular views and exciting ride experiences.
The small footprint of tower rides is an additional advantage for crowded city parks, like Gröna Lund in Stockholm,

As the boat approaches Gröna Lund, we see their three drop towers. 
Two of them are free fall rides with magnetic brakes to stop the fall. 

In Ikaros, the riders are also tilted to fall face down, which of course adds to the excitement and increases the scare factor. 

Indeed, drop towers come in many different forms, from the very tall and very intimidating to smaller, more family friendly versions. They also exist in underground forms. However the underground drop rides generally  employ a substantially shorter drop than the above ground versions 

The tower to the right is a Double Shot from S&S. It starts with a rapid upward launch and then 2 seconds of free fall weightlessness before landing on compressed air. After a couple of bounces the gondola is pulled up again and continues as a Turbo Drop, where the gondola accelerates downward - faster than Free fall. 

This is the Turbo Drop Gyldne Tårn in Tivoli Gardens in Copenhagen.
Watching the ride, moving up and down 
gives an outside perspective - as common in physics text books. 

If, instead, we SIT in the gondola, as here in a simulated ride, we see the ground moving up and down as we move down and then up again.  
We can also compare the two perspectives!

However, an important difference when you ride for real 
is that you also feel the forces required to change the motion. 
The forces you feel can be measured with accelerometers taken along on the ride

This figure shows the acceleration, velocity and elevation, based on data from the sensor carried in the vest. We can also look at the relation between velocity as the derivative of elevation - and change in elevation as the integral of velocity.

Using the screen shots we can mark the change in elevation between two images, proportional to the average velocity in that interval. The change in the velocity, then gives the acceleration.

The data for elevation and velocity can also be combined for a phase portrait, where the lower and lower bounces show up as smaller and smaller ellipses, while the gondola with the riders is brought back for unloading. 

To help connect the acceleration and forces to the motion, this clip includes an overlay on forces and acceleration in the simulated ride.

Yet another different representation of the motion in a drop tower can be obtained on special occasions, when a soft mug with just a small amount water may be taken along for the ride. As the fall starts, the water leaves the mug, as for these girls during a free fall part of a Space Shot ride. 

And when is time to leave the park -  let the fun continue when
you go home and work on your math and analyse your videos and data.