| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.05 |
| Score | 0% | 61% |
A box is resting on a smooth floor. Static friction is present:
if the coefficient of friction is greater than one |
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only if normal force is present |
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when an attempt is made to move the box |
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at all times |
For any given surface, the coefficient of static friction is higher than the coefficient of kinetic friction. More force is required to initally get an object moving than is required to keep it moving. Additionally, static friction only arises in response to an attempt to move an object (overcome the normal force between it and the surface).
For a hydraulic system, pressure applied to the input of the system will increase the pressure in which parts of the system?
everywhere in the system |
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the portions of the system at an altitude above the input |
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all of these are correct |
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the portions of the system at an altitude below the input |
Pascal's law states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. For a hydraulic system, this means that a pressure applied to the input of the system will increase the pressure everywhere in the system.
The work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. This defines which of the following?
Pascal's law |
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mechanical advantage |
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work-energy theorem |
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conservation of mechanical energy |
The work-energy theorem states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. Simply put, work imparts kinetic energy to the matter upon which the work is being done.
Two gears are connected and the larger gear drives the smaller gear. The speed of rotation will __________ and the torque will __________.
decrease, decrease |
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increase, increase |
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increase, decrease |
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decrease, increase |
Connected gears of different numbers of teeth are used together to change the rotational speed and torque of the input force. If the smaller gear drives the larger gear, the speed of rotation will be reduced and the torque will increase. If the larger gear drives the smaller gear, the speed of rotation will increase and the torque will be reduced.
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| 40% | |
| 320% | |
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