Explain why heat only flows spontaneously from a hot to cold object.

What is the difference between energy and power? What is a unit of power? How does speed relate to power?
Explain how a sound is actually a form of energy? In what medium do sound waves travel?
Give an example of change of energy from potential to kinetic; from kinetic to potential.
What is a trophic level? Give some examples. How much energy is lost at each trophic level?
If you eat 600 calories per day (roughly one dessert) below your energy needs, how long would it take to lose 10 pounds? How long would you have to walk (assuming 80 calories burned per mile walked) to lose 10 pounds?
What makes a good conductor of heat? What makes a good insulator?
Explain why heat only flows spontaneously from a hot to cold object.
In what way is aging an example of the second law of thermodynamics?
You are traveling to Europe, and the weather forecast says it is going to be 38oC. Should you wear shorts of a down jacket?