3/28 Physics update and homework due 4/4

Hi folks,

Today we combined several of our energy concepts into one big lab where the students had to find the energy efficiency of several different Hot Wheels cars. Their job was to find out how high they needed to start the cars on a ramp in order to get them to have enough energy to do a "loop de loop". They then compared the height of the loop de loop with the height of the starting point to find out how energy efficient the cars were.


Homework for our next class is to answer the following questions.


1. According to your data, what car was the most energy efficient?




2. Could you have done something to the track to make it more energy efficient? In other words, were there areas on the track that were stealing energy from your cars?




3. If the car had to be dropped from a higher point to go around the loop, was it more or less energy efficient?




4. If the car and track was 100% energy efficient, how high would you drop the car from?




5. Where did the car have the most potential energy?




6. Where did the car have the most kinetic energy?




7. If you dropped the car from a lower height than the top of the loop, could it go around the loop?




8. If the loop was 14 inches tall and a car had to be dropped from 36 inches to go around the loop, what's the energy efficiency of the car?



9. What caused the car to be less than 100% energy efficient?



10. What were some of the differences between your most energy efficient and your least energy efficient car?



11. Where did the energy come from that the car had at the top of the ramp?