Using the "Hot Wheels" cars and magnets set up a potential energy like the one shown in Figure 1.
You should have an arrangement like the one below:
Push the car so it turns around near the magnets. Then, sketch the approximate value of the total energy on the potential energy diagram. Mark the point where the car turns around as A. Describe your sketch below:
Now give the car a stronger push. What does the car do when it approaches point A (i.e. near the magnet)?
Sketch both the total energy level of this car and its potential energy. Mark the point where the car turns around as B. Indicate on this graph the approximate location of point A from the previous graph.
You should now have a sketch that looks something like Figure 4 below: