Which letter would be compression of a longitudinal wave?

Hydrogen and helium are both members of?

5400 j of energy are given off when a 50 g of aluminum pan changes temperature. does the temperature of the pan increase or decrease and by how much?

Mary starts from her house, walks 80 meters south, and stops to chat with her aunt on the sidewalk. after chatting for a few minutes, she walks 125 meters to the west to meet a friend and then walks 45 meters north with her friend to a cafe for lunch. overall, she takes 10 minutes to do all this. what is mary’s average speed?