All sound is created by ___ of a median

Selma made a diagram to compare convection and radiation. which label belongs in the area marked x? must involve temperature differences between substances or objects only occurs when molecules are in direct contact involves the movement of fluids based on density differences can occur where there is little or no matter

If anyone who can me with this hw? i would really appreciate it

A15 ohm resistor and a 25 ohm resistor are connected in a series to a 60 volt battery. what is the power used by each device