# Module 4 Study, from Apologia General Science

## Terms

undefined, object
copy deck
Define Simple machine
A device that reduces the amount of force needed to perform a task or changes the direction of a force
Define Force
A push or pull that changes the motion of an object
The amount by which force or motion is magnified in a simple machine
Define Diameter
The length of a straight line that travels from one side of a circle to another, while passing through the center of a circle
Define Circumference
The distance around a circle, equal to 3.1416 times the circle's diameter
How is applied science different from science?
Applied science differs from science in motive. In applied science, the goal is to make something better. In science, the goal is simply to learn.
Technology can result from accident, science, or applied science.
Identify each of the following as a science experiment or an applied science experiment:
a. An experiment to determine how to make light bulbs smaller
b. An experiment to understand what factors affect how water currents run in the ocean
Experiments (a) and (c) are applied science experiments, because the goal is to make something better.Experiments (b) and (d) are science
experiments, because the goal is to learn something. Even though the knowledge gained from experiments (b)and(d) might be useful, thatâ€™s not the primary goal. Since the primary goal is knowledge, they are science experiments.
Which of the following would be considered technology?
a. A classification scheme for all plants
b. A vaccination that will prevent horses from getting West Nile Virus
c. A new diet for teens that will lead to longer life
d. An unde
5. Items (b) and (c) are technology. They are not machines, but a vaccination for horses is something that makes life better, and a new diet for teens does the same.
List the six types of simple machines.
The lever, the pulley, the wheel and axle, the inclined plane, the wedge, and the screw.
Which two simple machines look identical?
The inclined plane and the wedge look identical.
What is the mechanical advantage of a lever in which the fulcrum is 10 inches from the resistance and 40 inches from the effort? What does the mechanical advantage in problem mean?
For levers, the mechanical advantage equation (you have to memorize it) is:
Mechanical advantage = (distance from fulcrum to effort) Ã· (distance from fulcrum to resistance)
Mechanical advantage = 40 Ã· 10 = 4
For levers, the mechanical advantage equation (you have to memorize it) is:
Mechanical advantage = (distance from fulcrum to effort) Ã· (distance from fulcrum to resistance)
Mechanical advantage = 40 Ã· 10 = 4 The mechanical advantage means that the effort is magnified by 4. It is impossible for the
lever described in the problem to be a third-class lever, so the mechanical advantage definitely magnifies the effort, not the speed. However, if the student includes that in the answer, it is fine.

This is a first class lever because the fulcrum is in the middle (like a childâ€™s see saw)
A shovel is an example of a lever. To what class does a shovel belong?
In a shovel, the part that does not move is the handle. You hold onto the handle with one hand, then you lift the middle of the shovel with the other. Thus, the effort is in the middle of the shovel. The resistance is in the shovelâ€™s head. Thus, the fulcrum is at one end, and the effort is between the fulcrum and the resistance. This is a third-class lever. (pg 90)
A childâ€™s see-saw is a lever. To what class does it belong?
In a see-saw, the middle does not move. One child is the resistance and the other is the effort. Thus, the fulcrum is between the effort and the resistance and it is a first class lever.
What is the mechanical advantage of a wheel and axle when the wheel has a diameter of 15 inches and the axle has a diameter of 3 inches? (discussion on pp 93-95)
The mechanical advantage of a wheel and axle is given by:
Mechanical advantage = (diameter of the wheel) ÷ (diameter of the axle)
Mechanical advantage = 15 ÷ 3 = 5
A block and tackle is composed of 6 pulleys that all work together. What is the mechanical advantage of the block and tackle system? Using the block and tackle system , how many feet of rope would have to be
pulled if a person wanted to lift a load
The mechanical advantage of a multiple-pulley system is simply equal to the number of pulleys that work together. Thus, the mechanical advantage is 6. (discussion pg 95). The mechanical advantage allows you to use less force when you lift, but you â€œpayâ€ for that by having to pull that much more rope. If the person wants to lift the load 1 foot and the mechanical advantage is 6, the person will need to pull 6 feet of rope.
What is the mechanical advantage of an inclined plane with a slope of 6 feet and a height of 2 feet? What is the mechanical advantage of a wedge with the same dimensions?
The mechanical advantage of an inclined plane is given by:
Mechanical advantage = (length of slope) ÷ (height)
Mechanical advantage = 6 ÷ 2 = 3 The mechanical advantage equation for a wedge is the same as it is for the inclined plane.
Since both have the same dimensions, the mechanical advantage is the same: 3.
A screw with a pitch of 0.1 inches is turned with a screwdriver whose diameter is 2 inches.
x
If you are having a hard time turning a screw, should you get a longer screwdriver or a fatter one?
x
A screw has a pitch of 0.05 inches. Its head has a diameter of 0.30 inches. What is the mechanical advantage of the screw if you grasp it on the head and screw it in?
x
What is the mechanical advantae of a screw with a pitch of 0.05 inches and a head with a diameter of 0.30 inches if you turn it with a screwdriver whose diameter is 1.5 inches?
x
A screwdriver in itself is a simple machine. What kind of simple machine is a screwdriver?
x
The combination of a screw and screwdriver is a combination of 2 simple machines. What are they?
x
Pary
Pary

24