| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.93 |
| Score | 0% | 59% |
Which of these will have the most impact on the kinetic energy of an object?
its weight |
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its direction |
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its speed |
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its mass |
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.
Coplanar forces:
have opposite dimensions |
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act in a common plane |
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pass through a common point |
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act along the same line of action |
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?
impact load |
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dynamic load |
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concentrated load |
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non-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.
Power is the rate at which:
input force is transferred to output force |
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friction is overcome |
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potential energy is converted into kinetic energy |
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work is done |
Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.
Which of the following represents the force a surface exerts when an object presses against it?
counter force |
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mass |
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normal force |
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friction |
Normal force (FN) represents the force a surface exerts when an object presses against it.