Students were asked to create roller coasters for marbles. The only requirement is that the roller coaster include at least one
hill that the marble must roll over in order for the roller coaster to be considered a success. Students are building their designs with marbles and foam tubing so there will be some air resistance and friction. What should the students keep in mind if they want to create a successful roller coaster? Question 23 options:
1)
Without an extra push at the bottom of the first hill, there is no way the car will make it back up a hill of any height because the marble doesn't have enough mass or velocity
2)
The hill should be at least a little lower than the starting height because some of the kinetic energy at the bottom of the first hill will be converted to other types of energy due to friction so it will not have as much potential energy at the top of the next hill
3)
The hill should be taller than the starting height because the marble will pick up speed on the downward hill and the increased velocity will allow it to travel higher on the next hill
4)
The hill should be the exact same height as the starting height because 100% of the kinetic energy at the bottom of the first hill will be converted back to potential energy at the top of the next hill
Since energy is lost in the roller coaster due to friction, the hill should little lower than the starting height since some of the kinetic energy at the bottom of the first hill is lost due to friction so it will not have as much potential energy at the top of the next hill.
A roller coaster is a good way to demonstrate the principle of conservation of energy. Recall that energy is neither created nor destroyed but can be converted from one form to another.
In a roller coaster, all the heights are not the same because energy is lost along the line. Therefore, the students must bear in mind that the hill should be at least a little lower than the starting height because some of the kinetic energy at the bottom of the first hill will be converted to other types of energy due to friction so it will not have as much potential energy at the top of the next hill.
