1. By definition, work is done when a _______ moves through a distance.   pressure   force   mass   Hint Half-n-half Clue   2. 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   3. A mass of 6 kg is raised through a vertical distance of 30 m. If the gravitational acceleration is 9.8 m s-2, then the potential energy gained by the mass is   180 J   1764 J   58.8 J   294 J   Half-n-half Clue   4. 'Energy can neither be created nor destroyed' is a statement of the   Law of Conservation of Electric Charges   Law of Conservation of Energy   Law of Conservation of Matter   Half-n-half Clue   5. A body loses 1176 J of potential energy in falling through 60 m. If the gravitational acceleration is 9.8 m s-2, then the body has a mass of   588 kg   20 kg   2 kg   120 kg   Half-n-half Clue   6. Both work and heat are measured in Joules.   True   False   7. If there is no friction, the efficiency of a machine can be greater than 100 %.   True   False