Module 4 Study, From Apologia General Science

Front 1

Define Simple machine

Back 1

A device that reduces the amount of force needed to perform a task or changes the direction of a force

Front 2

Define Force

Back 2

A push or pull that changes the motion of an object

Front 3

Define Mechanical advantage

Back 3

The amount by which force or motion is magnified in a simple machine

Front 4

Define Diameter

Back 4

The length of a straight line that travels from one side of a circle to another, while passing through the center of a circle

Front 5

Define Circumference

Back 5

The distance around a circle, equal to 3.1416 times the circle's diameter

Front 6

How is applied science different from science?

Back 6

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.

Front 7

What leads to technology?

Back 7

Technology can result from accident, science, or applied science.

Front 8

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
c. An experiment to figure out how to reduce electricity use of a light bulb.
d. An experiment to figure out the speed of water as it flows through East Australian current (Finding Nemo-water current)

Back 8

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, that’s not the primary goal. Since the primary goal is knowledge, they are science experiments.

Front 9

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 understanding of what causes renal failure in diabetics

Back 9

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.

Front 10

List the six types of simple machines.

Back 10

The lever, the pulley, the wheel and axle, the inclined plane, the wedge, and the screw.

Front 11

Which two simple machines look identical?

Back 11

The inclined plane and the wedge look identical.

Front 12

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?

Back 12

For levers, the mechanical advantage equation (you have to memorize it) is:
Mechanical advantage = (distance from fulcrum to effort) ÷ (distance from fulcrum to resistance)
Mechanical advantage = 40 ÷ 10 = 4
For levers, the mechanical advantage equation (you have to memorize it) is:
Mechanical advantage = (distance from fulcrum to effort) ÷ (distance from fulcrum to resistance)
Mechanical advantage = 40 ÷ 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 child’s see saw)

Front 13

A shovel is an example of a lever. To what class does a shovel belong?

Back 13

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 shovel’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)

Front 14

A child’s see-saw is a lever. To what class does it belong?

Back 14

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.

Front 15

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)

Back 15

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

Front 16

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 1 foot?

Back 16

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 “pay” 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.

Front 17

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?

Back 17

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.

Front 18

A screw with a pitch of 0.1 inches is turned with a screwdriver whose diameter is 2 inches.
What is the mechanical advantage?

Back 18

x

Front 19

If you are having a hard time turning a screw, should you get a longer screwdriver or a fatter one?

Back 19

x

Front 20

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?

Back 20

x

Front 21

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?

Back 21

x

Front 22

A screwdriver in itself is a simple machine. What kind of simple machine is a screwdriver?

Back 22

x

Front 23

The combination of a screw and screwdriver is a combination of 2 simple machines. What are they?

Back 23

x