| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.42 |
| Score | 0% | 68% |
Which of the following is not a characteristic of a ceramic?
chemically stable |
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low density |
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low corrosive action |
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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.
Friction resists movement in a direction __________ to the movement.
parallel |
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opposite |
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perpendicular |
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normal |
Friction resists movement. Kinetic (also called sliding or dynamic) friction resists movement in a direction opposite to the movement. Because it opposes movement, kinetic friction will eventually bring an object to a stop. An example is a rock that's sliding across ice.
An inclined plane increases ___________ to reduce ____________.
distance, force |
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force, distance |
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distance, power |
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force, 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.
| 90 ft⋅lb | |
| 15 ft⋅lb | |
| 10 ft⋅lb | |
| 30 ft⋅lb |
What type of load varies with time or affects a structure that experiences a high degree of movement?
impact load |
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static load |
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dynamic load |
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concentrated 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.