| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.18 |
| Score | 0% | 64% |
Which of the following is not a characteristic of a ceramic?
low density |
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low corrosive action |
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chemically stable |
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high melting point |
Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.
Power is the rate at which:
input force is transferred to output force |
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potential energy is converted into kinetic energy |
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work is done |
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friction is overcome |
Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.
What type of load creates different stresses at different locations on a structure?
static uniformly distributed load |
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impact load |
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non-uniformly distributed load |
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dynamic load |
A concentrated load acts on a relatively small area of a structure, a static uniformly distributed load doesn't create specific stress points or vary with time, a dynamic load varies with time or affects a structure that experiences a high degree of movement, an impact load is sudden and for a relatively short duration and a non-uniformly distributed load creates different stresses at different locations on a structure.
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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the portions of the system at an altitude below the input |
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everywhere in the system |
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the portions of the system at an altitude above 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.
Which of the following surfaces would have the highest coefficient of friction?
ice |
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marble |
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concrete |
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steel |
Coefficient of friction (μ) represents how much two materials resist sliding across each other. Smooth surfaces like ice have low coefficients of friction while rough surfaces like concrete have high μ.