The warm object loses energy and the cool object gains energy so that both objects stay at different temperatures. The warm object gains energy and the cool object loses energy so that both objects stay at different temperatures. The warm object loses energy and the cool object gains energy until both objects are the same temperature. The warm object gains energy and the cool object loses energy until both objects are the same temperature.
I gave my students this multiple choice question: What happens when a warm object is put inside a cooler object?

Only one answer is correct among these 4 choices:
- The warm object loses energy and the cool object gains energy so that both objects stay at different temperatures.
- The warm object gains energy and the cool object loses energy so that both objects stay at different temperatures.
- The warm object loses energy and the cool object gains energy until both objects are the same temperature.
- The warm object gains energy and the cool object loses energy until both objects are the same temperature.

Could you tell me which one is correct?

The warm object loses energy and the cool object gains energy until both objects are the same temperature.