| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.96 |
| Score | 0% | 59% |
An object's resistance to changes in direction is known as:
inertia |
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weight |
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kinetic energy |
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mass |
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 science that deals with motion and the forces that produce motion is called which of the following?
aeronautics |
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engineering |
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mechanics |
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physics |
Mechanics deals with motion and the forces that produce motion.
The advantage of using a third-class lever is that it increases:
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 |
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the speed of 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.
What is work?
Force per unit time |
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The movement of an object by a force |
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The potential for exertion |
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Force per unit distance |
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.
Assuming force applied remains constant, which of the following will result in more work being done?
moving the object farther |
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moving the object with more acceleration |
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moving the object with more speed |
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increasing the coefficient of friction |
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.