Which describes the position on a horizontal number line

What is the weight of a 8-kg substance in n, kn, kg·m/s2, kgf, lbm·ft/s2, and lbf?

Whithin which type of system is neither the total mass nor the total energy conserved ? a. open b. connected c. isolated d. closed

Which statements best describe energy? check all that apply. the total amount of energy in the universe remains constant. the total amount of energy in the universe changes constantly. energy cannot be converted from one form to another. energy can be converted from one form to another. energy cannot be created or destroyed. energy can be created or destroyed.