Solve this, dont knkw even the abc of it

Ben(55 kg) is standing on very slippery ice when junior(25kg) bumps into him. junior was moving at a speed of 8m/s before the collision and ben and junior embrace after the collision. find the speed of ben and junior as they move across the ice after the collision .

Select the word from the list that best fits the definition classification of most stars on the h-r diagram

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation