| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.20 |
| Score | 0% | 64% |
The mass of an object correlates to the size of the object but ultimately depends on:
the object's density |
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the object's potential energy |
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the object's weight |
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gravity |
Mass is a measure of the amount of matter in an object. In general, larger objects have larger mass than smaller objects but mass ultimately depends on how compact (dense) a substance is.
A wedge is most similar to what other type of simple machine?
first-class lever |
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second-class lever |
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third-class lever |
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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.
What is the first step to solving a problem where multiple forces are acting on an object?
calculate the total force |
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calculate the net force |
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calculate potential energy |
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calculate kinetic energy |
In mechanics, multiple forces are often acting on a particular object and, taken together, produce the net force acting on that object. Like force, net force is a vector quantity in that it has magnitude and direction.
Which of the following statements about drag is false?
drag occurs during movement through a fluid |
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slower objects experience more drag than faster objects |
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the amount of drag depends on the shape of an object |
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the amount of drag depends on the speed of an object |
Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.
What defines the mechanical advantage of a first class lever?
output force |
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position of the fulcrum |
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input force |
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output distance |
A first-class lever is used to increase force or distance while changing the direction of the force. The lever pivots on a fulcrum and, when a force is applied to the lever at one side of the fulcrum, the other end moves in the opposite direction. The position of the fulcrum also defines the mechanical advantage of the lever. If the fulcrum is closer to the force being applied, the load can be moved a greater distance at the expense of requiring a greater input force. If the fulcrum is closer to the load, less force is required but the force must be applied over a longer distance. An example of a first-class lever is a seesaw / teeter-totter.