Which of the following is an example of sound energy

Which energy transformation occurs in the core of a nuclear reactor? nuclear energy mechanical energy nuclear energy - thermal energy thermal energy -- nuclear energy mechanical energy - nuclear energy

As a car drives with its tires rolling freely without any slippage, the type of friction acting between the tires and the road is 100) a) static friction. b) kinetic friction. c) a combination of static and kinetic friction. d) neither static nor kinetic friction, but some other type of friction. e) it is impossible to tell what type of friction acts in this situation.

In a hydrogen molecule there are a total of four charges, 2 protons in the two nuclei, and 2 electrons. how many unique charge-pairs are there (without double counting)?