Measurements and Forces

Measurements:

Time:

In order to measure the time it takes for a roller coaster to complete it’s run, a few methods can be used. One way is using “front-to-back” times. To calculate the “front-to-back” time, a stopwatch is used. The stopwatch is started when the head car reaches a designated point. Timing is stopped when the rear of the train passes the same point. The speed would equal the length of the coaster train divided by the front-to-back time. The total time is then used to find the average velocity:

Average speed = total distance/beginning-to-end time

Another way to measure time is using “point-to-point” time measurement, in which a stopwatch would be used to time how long it took the coaster train to pass from designated point A to designated point B. Then the average speed is calculated:

Average speed = (distance between points A & B)(time to go between the two points)

Forces:

Vertical forces can be estimated on rides using the term of force factor (FF). Force factor is calculated below:

Force Factor = chair force on rider/weight of the rider = Force/mg

To understand the principal of the force factor, we will use an example of a rider, which weighs 200 pounds. When there is no acceleration, the vertical force factor is 1(normal). The passenger feels as if he weighs 200 pounds. At the bottom of a coaster hill, there is a force factor of 2. The rider feels as if he weighs 400 pounds. On coaster hilltops, the FF is 0.5 (half of the normal body weight). Now, the passenger feels as if he weighs half as much, or 100 pounds.

Astronauts and pilots often discuss the force as “pulling g’s”. Pulling 2 g’s is the same thing as having a force factor of 2. When forces are discussed, force factor and “g’s” are often used interchangeably.

Horizontal Forces are made by the back of the seat, friction between the rider and the seat, and the side of the car or the lap bar. These forces can be sideways, backwards, or forward. A forward force is when a rider feels pushed back into seat. A backward force causes a rider to have a feeling of being pushed forward. A force from the left pushes passengers to the right. A right force causes riders to be pushed to the left. Naturally, a stationary train exerts a 0 horizontal force (normal). The horizontal force factor is seldom more than 1 on a ride.