| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.78 |
| Score | 0% | 56% |
For a hydraulic system, pressure applied to the input of the system will increase the pressure in which parts of the system?
all of these are correct |
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everywhere in the system |
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the portions of the system at an altitude above the input |
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the portions of the system at an altitude below the input |
Pascal's law states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. For a hydraulic system, this means that a pressure applied to the input of the system will increase the pressure everywhere in the system.
| 11 ft. | |
| 13.64 ft. | |
| 6.82 ft. | |
| 20.45 ft. |
To balance this lever the torques at the green box and the blue arrow must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:
Rada = Rbdb
where a represents the green box and b the blue arrow, R is resistance (weight/force) and d is the distance from the fulcrum.Solving for da, our missing value, and plugging in our variables yields:
da = \( \frac{R_bd_b}{R_a} \) = \( \frac{75 lbs. \times 5 ft.}{55 lbs.} \) = \( \frac{375 ft⋅lb}{55 lbs.} \) = 6.82 ft.
Specific gravity is a comparison of the density of an object with the density of:
water |
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carbon |
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air |
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oil |
Specific gravity is the ratio of the density of equal volumes of a substance and water and is measured by a hyrdometer.
An inclined plane increases ___________ to reduce ____________.
distance, power |
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force, power |
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distance, force |
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force, distance |
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.
Lisa lifts a 25 pound box from the floor onto a loading dock 4 ft. off the ground. Sam slides the same box along a ramp to move it up another 4 ft. onto a flatbed truck. Who has done more work?
Sam |
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Lisa |
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Neither have done any work |
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They have done an equal amount of work |
Work is force multiplied by distance. Because both Connie and Sam moved the same weight the same distance they have done an equal amount of work. Sam employed the mechnacial advantage of an inclined plane so he exerted less effort to do the work but the amount of work done was still the same.