| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.25 |
| Score | 0% | 65% |
When it comes to force, mass and acceleration have what kind of relationship?
inverse |
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logarithmic |
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exponential |
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linear |
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.
| 6 | |
| 2 | |
| 7.5 | |
| 9 |
The mechanical advantage (MA) of a wedge is its length divided by its thickness:
MA = \( \frac{l}{t} \) = \( \frac{30 in.}{5 in.} \) = 6
Concurrent forces:
act in a common dimension |
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act along the same line of action |
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pass through a common point |
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act in a common plane |
Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.
What type of load is sudden and for a relatively short duration?
non-uniformly distributed load |
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dynamic load |
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impact 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.
Which of the following will increase the mechanical advantage of a second-class lever?
move the fulcrum between the force and the object being lifted |
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move the object being lifted farther away from the fulcrum |
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move the object being lifted closer to the fulcrum |
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decrease the length of the lever |
A second-class lever is used to increase force on an object in the same direction as the force is applied. This lever requires a smaller force to lift a larger load but the force must be applied over a greater distance. The fulcrum is placed at one end of the lever and mechanical advantage increases as the object being lifted is moved closer to the fulcrum or the length of the lever is increased. An example of a second-class lever is a wheelbarrow.