1. By definition, work is done when a _______ moves through a distance.   pressure   mass   force   Hint Half-n-half Clue   2. Efficiency of a machine equals   Work Output / (Work Input + Work Output) × 100 %   Work Input / Work Output × 100 %   Work Output / Work Input × 100 %   Work Input / (Work Input + Work Output) × 100 %   Half-n-half Clue   3. Kinetic energy of a body in motion equals the product of half its mass and the square of its _______   velocity   distance   acceleration   Half-n-half Clue   4. When a current is supplied by a battery, _______ energy is converted to electrical energy.   nuclear   chemical   mechanical   Half-n-half Clue   5. A boy throws a ball vertically upwards from ground level. If the ball reaches a maximum height of 250 m and the gravitational acceleration is 9.8 m/s2, with what speed did the boy throw the ball?   35 m/s   50 m/s   70 m/s   10 m/s   Half-n-half Clue   6. A mass of 2 kg is raised through a vertical distance of 60 m. If the gravitational acceleration is 9.8 m s-2, then the potential energy gained by the mass is   588 J   19.6 J   120 J   1176 J   Half-n-half Clue   7. A body loses 2156 J of potential energy in falling through 55 m. If the gravitational acceleration is 9.8 m s-2, then the body has a mass of   4 kg   539 kg   220 kg   39 kg   Half-n-half Clue