| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.91 |
| Score | 0% | 58% |
A fixed pulley has a mechanical advantage of:
-1 |
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2 |
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1 |
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0 |
A fixed pulley is used to change the direction of a force and does not multiply the force applied. As such, it has a mechanical advantage of one. The benefit of a fixed pulley is that it can allow the force to be applied at a more convenient angle, for example, pulling downward or horizontally to lift an object instead of upward.
A wedge converts force applied to its blunt end into force __________ its inclined surface.
along |
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perpendicular to |
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parallel to |
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opposite to |
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.
Which of the following statements about drag is false?
the amount of drag depends on the shape of an object |
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drag occurs during movement through a fluid |
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the amount of drag depends on the speed of an object |
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slower objects experience more drag than faster objects |
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.
A truck is using a rope to pull a car. Tension in the rope is greatest in which of the following places?
tension is equal in all parts of the rope |
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in the middle |
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near the car |
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near the truck |
Tension is a force that stretches or elongates something. When a cable or rope is used to pull an object, for example, it stretches internally as it accepts the weight that it's moving. Although tension is often treated as applying equally to all parts of a material, it's greater at the places where the material is under the most stress.
An inclined plane increases ___________ to reduce ____________.
distance, force |
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force, power |
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force, distance |
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distance, 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.