| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.11 |
| Score | 0% | 62% |
What type of load creates different stresses at different locations on a structure?
non-uniformly distributed load |
|
impact load |
|
dynamic load |
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static uniformly distributed 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.
Which of the following is not a characteristic of a ceramic?
chemically stable |
|
low corrosive action |
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high melting point |
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low density |
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.
Which of the following is not a modulus of elasticity?
stress modulus |
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stretch modulus |
|
bulk modulus |
|
shear modulus |
The modulus of elasticity measures how much a material or structure will deflect under stress. Stretch modulus is longitudinal stretch (like stretching raw bread dough), shear modulus is longitudinal deflection (like the horizontal displacement of a stack of magzines when a heavy object is placed upon them), and bulk modulus is compression of volume (like the compression of a loaf of bread under a heavy can at the bottom of a grocery bag).
Potential energy is energy that has the potential to be converted into what?
heat |
|
power |
|
kinetic energy |
|
work |
Potential energy is the energy of an object by virtue of its position relative to other objects. It is energy that has the potential to be converted into kinetic energy.
| 192.5 lbs. | |
| 440 lbs. | |
| 48.13 lbs. | |
| 96.25 lbs. |
To balance this lever the torques on each side of the fulcrum must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:
Rada = Rbdb
where a represents the left side of the fulcrum and b the right, R is resistance (weight) and d is the distance from the fulcrum.Solving for Rb, our missing value, and plugging in our variables yields:
Rb = \( \frac{R_ad_a}{d_b} \) = \( \frac{55 lbs. \times 7 ft.}{8 ft.} \) = \( \frac{385 ft⋅lb}{8 ft.} \) = 48.13 lbs.