Having realized that their diagram was not relevant, the students redrew it, but kept their narrative the same.

Student Narrative:

The launched cart is moving toward the stationary target cart and when they collide there is a contact push/pull interaction between them. The energy giver during this interaction is the launched cart, and energy is transferred from it to the target cart, which is the energy receiver. Because of this energy transfer, the kinetic energy of the launched cart decreases while the kinetic energy of the target cart increases. Since the target cart was initially at rest with a speed of zero and no kinetic energy, this increase in its kinetic energy means its speed is no longer zero, which in turn means that it starts to move.

Student Revised Energy Giver and Receiver Diagram

Evaluate the Revised Diagram

What is your evaluation of the revised explanation in terms of whether it is accurate or not?

Which graph best represents the motion of the cart?

A The explanation is accurate.
B It is not accurate because it does not use appropriate ideas about energy transfers.
C It is not accurate because it does not use appropriate ideas about energy changes.
D None of the above.

Check answer