| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.85 |
| Score | 0% | 57% |
Which of the following represents the force a surface exerts when an object presses against it?
normal force |
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mass |
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friction |
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counter force |
Normal force (FN) represents the force a surface exerts when an object presses against it.
Concurrent forces:
act in a common plane |
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act in a common dimension |
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pass through a common point |
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act along the same line of action |
Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.
The mechanical advantage of a wheel and axle is equal to the:
ratio of the diameters of the wheels |
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difference in the diameters of the wheels |
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difference in the lengths of the axles |
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length of the axle |
A wheel and axle uses two different diameter wheels mounted to a connecting axle. Force is applied to the larger wheel and large movements of this wheel result in small movements in the smaller wheel. Because a larger movement distance is being translated to a smaller distance, force is increased with a mechanical advantage equal to the ratio of the diameters of the wheels. An example of a wheel and axle is the steering wheel of a car.
When it comes to force, mass and acceleration have what kind of relationship?
inverse |
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linear |
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exponential |
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logarithmic |
Newton's Second Law of Motion states that "The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object." This Law describes the linear relationship between mass and acceleration when it comes to force and leads to the formula F = ma or force equals mass multiplied by rate of acceleration.
A fixed pulley is useful for which of the following?
multiplying the input distance |
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changing the direction of the input force |
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changing the direction of the output force |
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multiplying the input force |
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.