| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.03 |
| Score | 0% | 61% |
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.
Two or more pulleys used together are called:
block and tackle |
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gears |
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wheel and axle |
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third-class lever |
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.
What is the first step to solving a problem where multiple forces are acting on an object?
calculate potential energy |
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calculate kinetic energy |
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calculate the total force |
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calculate the net force |
In mechanics, multiple forces are often acting on a particular object and, taken together, produce the net force acting on that object. Like force, net force is a vector quantity in that it has magnitude and direction.
A wedge converts force applied to its blunt end into force __________ its inclined surface.
opposite to |
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parallel to |
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perpendicular to |
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along |
The wedge is a moving inclined plane that is used to lift, hold, or break apart an object. A wedge converts force applied to its blunt end into force perpendicular to its inclined surface. In contrast to a stationary plane where force is applied to the object being moved, with a wedge the object is stationary and the force is being applied to the plane. Examples of a wedge include knives and chisels.
A truck is using a rope to pull a car. Tension in the rope is greatest in which of the following places?
near the truck |
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in the middle |
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near the car |
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tension is equal in all parts of the rope |
Tension is a force that stretches or elongates something. When a cable or rope is used to pull an object, for example, it stretches internally as it accepts the weight that it's moving. Although tension is often treated as applying equally to all parts of a material, it's greater at the places where the material is under the most stress.