| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
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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all of these are correct |
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the portions of the system at an altitude below the input |
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the portions of the system at an altitude above 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.
Which of these is the formula for kinetic energy?
\(KE = mgh\) |
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\(KE = {1 \over 2}mh^2\) |
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\(KE = {m \over v^2 }\) |
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\(KE = {1 \over 2}mv^2\) |
Kinetic energy is the energy of movement and is a function of the mass of an object and its speed: \(KE = {1 \over 2}mv^2\) where m is mass in kilograms, v is speed in meters per second, and KE is in joules. The most impactful quantity to kinetic energy is velocity as an increase in mass increases KE linearly while an increase in speed increases KE exponentially.
| 4 ft. | |
| 40 ft. | |
| 8 ft. | |
| 2 ft. |
Win = Wout
Feffort x deffort = Fresistance x dresistance
In this problem, the effort work is 320 ft⋅lb and the resistance force is 80 lbs. and we need to calculate the resistance distance:
Win = Fresistance x dresistance
320 ft⋅lb = 80 lbs. x dresistance
dresistance = \( \frac{320ft⋅lb}{80 lbs.} \) = 4 ft.
The mechanical advantage of a third class lever is always:
equal to one |
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greater than one |
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not equal to one |
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less than one |
A third class lever is designed to multiply distance and speed at the expense of effort force. Because the effort force is greater than the resistance, the mechanical advantage of a third class lever is always less than one.
An example of a third class lever is a broom. The fulcrum is at your hand on the end of the broom, the effort force is your other hand in the middle, and the resistance is at the bottom bristles. The effort force of your hand in the middle multiplies the distance and speed of the bristles at the bottom but at the expense of producing a brushing force that's less than the force you're applying with your hand.
On Earth, acceleration due to gravity (g) is approximately __________.
1 m/s |
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9.8 m/s2 |
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6.67 x 10-11 m/s2 |
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1 m/s2 |
Newton's Law of Univeral Gravitation defines the general formula for the attraction of gravity between two objects: \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) . In the specific case of an object falling toward Earth, the acceleration due to gravity (g) is approximately 9.8 m/s2.