1. Kinetic energy of a body in motion equals the product of half its mass and the square of its _______   acceleration   distance   velocity   Hint Half-n-half Clue   2. Efficiency of a machine equals   Work Output / (Work Input + Work Output) × 100 %   Work Output / Work Input × 100 %   Work Input / Work Output × 100 %   Work Input / (Work Input + Work Output) × 100 %   Half-n-half Clue   3. If there is no friction, the efficiency of a machine can be greater than 100 %.   True   False   4. A machine that produces 85 J of work by using 100 J of energy has an efficiency of   15 J   15 %   17 J   85 %   Half-n-half Clue   5. When a current is supplied by a battery, _______ energy is converted to electrical energy.   chemical   mechanical   nuclear   Half-n-half Clue   6. _______ is the capacity to do work.   Force   Pressure   Energy   Half-n-half Clue   7. A mass of 2 kg is raised through a vertical distance of 20 m. If the gravitational acceleration is 9.8 m s-2, then the potential energy gained by the mass is   19.6 J   40 J   392 J   196 J   Half-n-half Clue