| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.52 |
| Score | 0% | 50% |
Which of these will have the most impact on the kinetic energy of an object?
its mass |
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its weight |
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its speed |
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its direction |
Kinetic energy is the energy of movement and is a function of the mass of an object and its speed: \(KE = {1 \over 2}mv^2\) where m is mass in kilograms, v is speed in meters per second, and KE is in joules. The most impactful quantity to kinetic energy is velocity as an increase in mass increases KE linearly while an increase in speed increases KE exponentially.
What is work?
The movement of an object by a force |
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Force per unit distance |
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The potential for exertion |
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Force per unit time |
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. By definition, work is the displacement of an object resulting from applied force.
What type of load varies with time or affects a structure that experiences a high degree of movement?
static load |
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dynamic load |
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concentrated 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.
What's the last gear in a gear train called?
idler gear |
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driven gear |
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output gear |
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driver gear |
A gear train is two or more gears linked together. Gear trains are designed to increase or reduce the speed or torque outpout of a rotating system or change the direction of its output. The first gear in the chain is called the driver and the last gear in the chain the driven gear with the gears between them called idler gears.
The advantage of using a third-class lever is that it increases:
the speed of the load |
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the distance traveled by the load |
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the mechanical advantage of the lever |
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the force applied to the load |
A third-class lever is used to increase distance traveled by an object in the same direction as the force applied. The fulcrum is at one end of the lever, the object at the other, and the force is applied between them. This lever does not impart a mechanical advantage as the effort force must be greater than the load but does impart extra speed to the load. Examples of third-class levers are shovels and tweezers.