How is the propulsion necessary to move a spacecraft through space different from the propulsion necessary to move an airplane through the air?

Which of these describe conduction transfer of heat between two objects that are touching transfer of heat by the actual movement of war matter the process in which energy is imitated by one of the object transmitted through space and absorbed by another a process in which energy is released by the molecules breaking apart

A500g object falls off a cliff and losers 100 j from its gravitational potential energy store. if the gravitational field strength g=9.8n/kg, how high is the cliff?

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.