The heat is used to break the bonds between the ice molecules as they turn into a liquid phase. Since the average kinetic energy of the molecules does not change at the moment of melting, the temperature of the molecules does not change.
Answer:
The total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision.
friction is the resistance that one surface or object encounters when moving over another. Due to gravity pulling everything down things need to friction in order to move
i hope this helps :/