| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.29 |
| Score | 0% | 66% |
Torque involves a perpendicular force applied to a lever arm that moves around a center of rotation. Increasing the length of the lever arm will do which of the following?
increase torque |
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decrease applied force |
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decrease torque |
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increase applied force |
Torque measures force applied during rotation: τ = rF. Torque (τ, the Greek letter tau) = the radius of the lever arm (r) multiplied by the force (F) applied. Radius is measured from the center of rotation or fulcrum to the point at which the perpendicular force is being applied. The resulting unit for torque is newton-meter (N-m) or foot-pound (ft-lb).
Lisa lifts a 25 pound box from the floor onto a loading dock 4 ft. off the ground. Sam slides the same box along a ramp to move it up another 4 ft. onto a flatbed truck. Who has done more work?
They have done an equal amount of work |
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Sam |
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Lisa |
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Neither have done any work |
Work is force multiplied by distance. Because both Connie and Sam moved the same weight the same distance they have done an equal amount of work. Sam employed the mechnacial advantage of an inclined plane so he exerted less effort to do the work but the amount of work done was still the same.
The mass of an object correlates to the size of the object but ultimately depends on:
the object's weight |
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gravity |
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the object's potential energy |
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the object's density |
Mass is a measure of the amount of matter in an object. In general, larger objects have larger mass than smaller objects but mass ultimately depends on how compact (dense) a substance is.
An object's resistance to changes in direction is known as:
mass |
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weight |
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inertia |
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kinetic energy |
The more mass a substance has the more force is required to move it or to change its direction. This resistance to changes in direction is known as inertia.
The standard unit of energy is the:
Joule |
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Volt |
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Watt |
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Horsepower |
The Joule (J) is the standard unit of energy and has the unit \({kg \times m^2} \over s^2\).