# Physical Science

## Chapter 5: Work and Machines

### Work and Machines Self-Check Quiz-Eng.

 1. How much work do you do when you lift your 10.0 kg sister to a height of 1.5 m? A) 150 J B) 15 J C) 15 N D) 15 W 2. If the radius of a doorknob is 5.0 cm and the radius of its inner rod is 1.25 cm, what is the mechanical advantage? A) 1.2 B) 4.0 C) 5.0 D) 6.2 3. When a machine does work on an object the output work is A) always less than the input work. B) always equal to the input work. C) always greater than the input work. D) sometimes equal to the input work. 4. If the distance between the input force and the fulcrum is 2.0 m and the distance between the output force and the fulcrum is 8.0 m, what is the ideal mechanical advantage? (4.0K) A) 1.0 B) 0.25 C) 4.0 D) 6.0 5. This class of lever is represented by a (4.0K) A) nail puller B) door hinge C) rake D) wheelbarrow 6. What type of simple machine does this illustration represent? (7.0K) A) second class lever B) screw C) wheel and axle D) pulley 7. Using this pulley system, how much force do you need to exert to lift a 500.0 N box? (7.0K) A) 100.0 N B) 250.0 N C) 500.0 N D) 125.0 N 8. The efficiency of this pulley system is A) exactly 100% B) exactly 400% C) greater than 100% D) less than 100% 9. A machine can do any of the following, except A) increase work B) increase distance C) increase force D) change direction 10. What is the ideal mechanical advantage of an inclined plane that is 6.0 m long and 1.5 m high? A) 4.0 B) .020 C) 1.5 D) 4.5