Consider reading the problem situation (on first slide) as a whole class. Then after answering questions about the situation, ask pairs of students discuss solutions. Have students take notes about their discussions.
You may wish to have pairs share out their ideas. After all discussions, ask each student write his or her own response.
: As the text states, a car posed at the top of roller coaster A, which has the steepest inclines and descents, has greater potential energy than a car at the top of roller coaster B. As your students discovered when investigating children swinging, when the cars are at the bottom of each incline, they will have the maximum kinetic energy and no potential energy. When the cars reach the top of the first hill, they again have more potential energy and less kinetic. When the cars reach the bottom of the loop-the-loop, the energy is all kinetic. At the beginning of the loop-the-loop, car A has dropped a greater distance and gone down a steeper incline than car B did, so car A will have greater kinetic energy than car B. Car A will also have a greater momentum than car B, because its velocity is greater. From the drawing, it appears that the kinetic energy for car A will be more than sufficient to carry the car to the top of the loop and around the loop. But the kinetic energy of car B probably won’t be sufficient to carry it to the top of the loop. And for a young cousin hanging upside down, that is a precarious position!