Question

1. click and drag the skater. drop the skater at the top of one end of the half pipe. watch the skater go back and forth on the half pipe. answer the following questions.

what is different about how the skater moves on this track?
the skater goes faster because the one is higher than the other one.

1. check the bar graph option again. put the skater back at the top and watch how the bar graphs move. explain what happens to each energy from the time the skater starts to when the skater stops.

kinetic energy
potential energy
thermal energy (heat)
total energy

1. go back to the intro track. this track has no friction. what do you notice about the amount of thermal energy if you compare the intro track to the friction track?

1. write an explanation for why the skater stops on the friction track. be sure to use the following terms in your explanation: kinetic energy, potential energy, thermal energy, total energy

1. check the options for the playground track at the very bottom of the screen.

Explanation:

1. When the skater starts at the top, it has maximum potential energy (due to height) and zero kinetic energy (as it is at rest). As it moves down the half - pipe, potential energy is converted to kinetic energy. Friction causes some of the mechanical energy (sum of kinetic and potential) to be converted into thermal energy. When the skater stops, all of its initial mechanical energy has been converted into thermal energy through friction.
2. The INTRO track likely has less friction compared to the FRICTION track. So, less thermal energy is generated on the INTRO track. On the FRICTION track, more thermal energy is produced because more work is done against friction.
3. The skater stops on the FRICTION track because friction acts against its motion. Initially, the skater has potential energy at the top of the track. As it moves, this potential energy is converted into kinetic energy. But due to friction, kinetic energy is gradually converted into thermal energy. As more and more kinetic energy is lost as thermal energy, the skater slows down and eventually stops. The total energy of the skater - Earth system remains constant, but it is continuously being transformed from mechanical energy (kinetic + potential) to thermal energy.

Answer:

1. Initial potential energy converts to kinetic and thermal energy until all is thermal at stop.
2. Less thermal energy on INTRO track, more on FRICTION track due to higher friction on latter.
3. Friction converts skater's mechanical energy to thermal energy, causing it to stop.