| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.04 |
| Score | 0% | 61% |
What type of load creates different stresses at different locations on a structure?
dynamic load |
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impact load |
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non-uniformly distributed 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.
Force of friction due to kinetic friction is __________ the force of friction due to static friction.
lower than |
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opposite |
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the same as |
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higher than |
The formula for force of friction (Ff) is the same whether kinetic or static friction applies: Ff = μFN. To distinguish between kinetic and static friction, μk and μs are often used in place of μ.
The steering wheel of a car is an example of which type of simple machine?
wheel and axle |
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first-class lever |
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fixed pulley |
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block and tackle |
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.
Assuming force applied remains constant, which of the following will result in more work being done?
moving the object farther |
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moving the object with more speed |
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increasing the coefficient of friction |
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moving the object with more acceleration |
Work is accomplished when force is applied to an object: W = Fd where F is force in newtons (N) and d is distance in meters (m). Thus, the more force that must be applied to move an object, the more work is done and the farther an object is moved by exerting force, the more work is done.
Normal force is generally equal to the __________ of an object.
mass |
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density |
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weight |
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coefficient of friction |
Normal force arises on a flat horizontal surface in response to an object's weight pressing it down. Consequently, normal force is generally equal to the object's weight.