| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.25 |
| Score | 0% | 65% |
A screw is most like which of the following other simple machines?
wheel and axle |
|
first-class lever |
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inclined plane |
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block and tackle |
A screw is an inclined plane wrapped in ridges (threads) around a cylinder. The distance between these ridges defines the pitch of the screw and this distance is how far the screw advances when it is turned once. The mechanical advantage of a screw is its circumference divided by the pitch.
A wedge is most similar to what other type of simple machine?
third-class lever |
|
second-class lever |
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first-class lever |
|
inclined plane |
The wedge is a moving inclined plane that is used to lift, hold, or break apart an object. A wedge converts force applied to its blunt end into force perpendicular to its inclined surface. In contrast to a stationary plane where force is applied to the object being moved, with a wedge the object is stationary and the force is being applied to the plane. Examples of a wedge include knives and chisels.
Collinear forces:
act in a common plane |
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pass through a common point |
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act along the same line of action |
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are unrelated to each other |
Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.
Hydraulics is the transmission of force through the use of which of the following?
liquids |
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torque |
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air pressure |
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gear systems |
Hydraulics is the transmission of force through the use of liquids. Liquids are especially suited for transferring force in complex machines because they compress very little and can occupy very small spaces. Hydraulic pressure is calculated by dividing force by the area over which it is applied: P = F/A where F is force in pounds, A is area in square inches, and the resulting pressure is in pounds per square inch (psi).
An inclined plane increases ___________ to reduce ____________.
force, distance |
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distance, power |
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distance, force |
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force, power |
An inclined plane is a simple machine that reduces the force needed to raise an object to a certain height. Work equals force x distance and, by increasing the distance that the object travels, an inclined plane reduces the force necessary to raise it to a particular height. In this case, the mechanical advantage is to make the task easier. An example of an inclined plane is a ramp.