| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.20 |
| Score | 0% | 64% |
Potential energy is energy that has the potential to be converted into what?
power |
|
heat |
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kinetic energy |
|
work |
Potential energy is the energy of an object by virtue of its position relative to other objects. It is energy that has the potential to be converted into kinetic energy.
Which of the following is not true of a first-class lever?
increases distance |
|
increases force |
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changes the direction of force |
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decreases distance |
A first-class lever is used to increase force or distance while changing the direction of the force. The lever pivots on a fulcrum and, when a force is applied to the lever at one side of the fulcrum, the other end moves in the opposite direction. The position of the fulcrum also defines the mechanical advantage of the lever. If the fulcrum is closer to the force being applied, the load can be moved a greater distance at the expense of requiring a greater input force. If the fulcrum is closer to the load, less force is required but the force must be applied over a longer distance. An example of a first-class lever is a seesaw / teeter-totter.
The science that deals with motion and the forces that produce motion is called which of the following?
physics |
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engineering |
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aeronautics |
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mechanics |
Mechanics deals with motion and the forces that produce motion.
| 8.5 | |
| 7 | |
| 2 | |
| 14 |
The mechanical advantage (MA) of a wedge is its length divided by its thickness:
MA = \( \frac{l}{t} \) = \( \frac{14 in.}{2 in.} \) = 7
Assuming force applied remains constant, which of the following will result in more work being done?
increasing the coefficient of friction |
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moving the object with more acceleration |
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moving the object with more speed |
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moving the object farther |
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.