True or False:
Less power is required while lifting a box up quickly than while slowly lifting it.
A source of energy is required to do work.
Without friction or work by an external force, the sum of the potential and kinetic energies of a body is constant.
Work cannot be done in the absence of motion.
Energy conservation law for a projectile (no friction): Potential energy increase equals the kinetic energy decrease.
Work is done when the form of energy changes.