| 1. Identify the lever class in each of the diagrams at the right AND explain why you identified each as that lever class. |  |
Multiple Choice Section
1. There are _____ types of simple machines.
(1.) three (2.) six
(2.) eight
(4.) ten
2. The use of a force to move an object some distance
is called
(1.) mass (2.) work
(3.) power (4.) time
3. In a perfectly efficient machine, the work input
_________ work output.
(1.) is equal to
(2.) is greater than (3.) is less than (4.)
is independent of
4. The _____ of a machine is the number of times it
multiplies the effort force.
(1.) efficiency
(2.) power (3.) mechanical advantage (4.) resistance
5. An inclined plane in spiral rotation is called
a(n)
(1.) wedge (2.) screw
(3.) lever (4.) pulley
6. If it takes 500 Joules to move an object
in 10 seconds, what is the power output?
(1.) 50 N. (2.)
5,000 N. (4.) 5,000 W. (4.) 50 W.
7. The basic metric system unit of power is the (1.) Joule (2.) Newton (3.) Meter (4.) Watt
8. What do we call the rate at which work is done?
(1.) Efficiency (2.) Work input
(3.) Work output
(4.) Power
9. Which is false about simple machines? (1.)
Machines increase the amount of work which is done.
(2.) Machines may multiply
force. (3.) Machines may increase the rate at which work is done.
(4.) Machines can change
the direction of a force to suit human convenience.
10. If a person weighing 400 N. takes 6 seconds to walk up a staircase
that is 3 meters high,
what is his power output?
(1.) 200 W. (2.) 1,200 W. (3.) 6,000 W. (4.) 7,200 W.
11. In using machines, work output is always _______ work input.
(1.) greater than
(2.) less than
(3.) the same as (4.) unrelated to
12. The fixed point of a lever is called the (1.) effort
arm (2.) fulcrum (3.) resistance arm
(4.) pivot arm
13. A wheel and axle is a(n) _______ machine. (1.) ideal
(2.) compound
(3.) simple (4.) automotive
14. The screw is a type of (1.) wedge (2.) inclined plane (3.) gear (4.) lever
15. Which of these does not represent work done on a rock in the
scientific sense?
(1.) lifting a rock
(2.) throwing a rock (3.) holding a rock (4.) dropping
a rock
16. For work to be done, _____ must be exerted through a distance.
(1.) mass (2.) specific
heat (3.) potential energy (4.) a force
17. In which of these situations is NO work done?
(1.) holding a box two feet off
the floor (2.) carrying a box across the room
(3.) pushing a box across the
floor (4.) carrying a box upstairs
18. The amount of work done on an object can be increased by
(1.) increasing the speed with which
the object moves.
(2.) decreasing the speed with which
the object moves.
(3.) increasing the distance the object
moves.
(4.) decreasing the distance the object
moves.
19. Which of the following is NOT true about machines?
(1.) They can reduce the
amount of work that must be done.
(2.) They can change the
amount of force required.
(3.) They can change the
distance over which a force is exerted.
(4.) They can change the
direction in which a force is exerted.
20. Mechanical advantage can be increased by
(1.) increasing input force.
(2.) increasing output force.
(3.) increasing both output and
input force.
(4.) decreasing both output and
input force.
21. A machine with 100% efficiency has no (1.) input force.
(2.) output force.
(3.) mechanical advantage. (4.) friction.
22. The pivot point of a lever is called a(n) (1.) wedge.
(2.) gear.
(3.) fulcrum. (4.) simple
machine.
23. A pair of scissors is an example of a(n) (1.)
inclined plane.
(2.) lever. (3.) wedge.
(4.) wheel and axle.
24. A wedge is made up of a(n) (1.) inclined plane. (2.)
lever.
(3.) pulley. (4.) wheel
and axle.
True-False Section
1. Compound machines are combinations of one or more simple machines.
2. A wheel and axle is really a lever that rotates in a circle.
3. A screw is a flat slanted surface with no moving parts.
4. A wedge is an inclined planes that moves.
5. Work input is the amount of work done by the machine
6. Mechanical advantage is the numerical value that indicates
how many times a machine will
multiply the user's effort force.
7. Acceleration is using an unbalanced force to move an object over a distance.
8. A screw is an inclined plane in spiral rotation.
9. A pulley is a grooved wheel with a rope.
Short Answer Questions
| 1. Identify the lever class in each of the diagrams at the right AND explain why you identified each as that lever class. | |
2. List the six major types of simple machines.
3. Explain how a simple machine differs from a compound
machine.
4. Show all the given information, formulae, and work
to the following problems.
A box is pushed across a surface using a force of 50 Newtons to slide the box 4 meters in 10 seconds.
(a.) What is the work that is done to move this box?
(b.) How much power is exerted moving this box?