How is net force calculated when two forces act on an object in opposite directions?

Iflow from a warmer object to a cooler object until both objects are the same temperature what am i?

When the velocity of an object is doubled, by what factor is its momentum changed? by what factor is its kinetic energy changed? a) the momentum is zero. b) the momentum is not zero. c) difficult to say.

What is the name for the remnant of an asymptotic giant that has lost its shells? black dwarf white dwarf yellow giant black hole