| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.07 |
| Score | 0% | 61% |
Which of the following is not a type of simple machine?
lever |
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pulley |
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screw |
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gear |
The six types of simple machines are the lever, wheel and axle, pulley, inclined plane, wedge, and screw.
What type of load doesn't create specific stress points or vary with time?
non-uniformly distributed load |
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concentrated load |
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static uniformly distributed load |
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impact 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 any given surface, the coefficient of static friction is ___________ the coefficient of kinetic friction.
lower than |
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equal to |
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higher than |
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opposite |
For any given surface, the coefficient of static friction is higher than the coefficient of kinetic friction. More force is required to initally get an object moving than is required to keep it moving. Additionally, static friction only arises in response to an attempt to move an object (overcome the normal force between it and the surface).
When it comes to force, mass and acceleration have what kind of relationship?
logarithmic |
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linear |
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inverse |
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exponential |
Newton's Second Law of Motion states that "The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object." This Law describes the linear relationship between mass and acceleration when it comes to force and leads to the formula F = ma or force equals mass multiplied by rate of acceleration.
The mechanical advantage of a block and tackle is equal to which of the following?
the number of pulleys |
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the number of connecting ropes |
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the number of loads |
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the number of input forces |
Two or more pulleys used together constitute a block and tackle which, unlike a fixed pulley, does impart mechanical advantage as a function of the number of pulleys that make up the arrangement. So, for example, a block and tackle with three pulleys would have a mechanical advantage of three.