Select True or False for each statement.
1) Without friction, and in the absence of external forces, the sum of the potential and kinetic energies of a body is constant.
2) More power is required while slowly lifting a box than while lifting it up quickly.
3) Energy is required to do work.
4) Energy conservation law for a projectile (no friction): Potential energy increase equals the kinetic energy decrease.
5) Work cannot be done in the absence of motion.
6) Work is done when the form of energy changes.