Question

which of these observations provide evidence that an energy change has occurred? choose 2 answers: a an object’s temperature changes. b two repelling objects remain at rest. c an object slows down. d two objects interact without making a sound.

Explanation:

• Option A: Temperature change is a sign of energy transfer (e.g., heat energy change), so it shows an energy change.
• Option B: If two repelling objects are at rest, there's no work done or energy transfer (force but no displacement), so no energy change.
• Option C: An object slowing down means its kinetic energy is decreasing (energy change, likely due to work done by friction or other forces).
• Option D: Interaction without sound doesn't necessarily imply energy change (e.g., magnetic interaction with no motion or temperature change may have no obvious energy change).

Answer:

A. An object’s temperature changes.
C. An object slows down.