| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.33 |
| Score | 0% | 67% |
The mass of an object correlates to the size of the object but ultimately depends on:
the object's density |
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the object's weight |
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gravity |
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the object's potential energy |
Mass is a measure of the amount of matter in an object. In general, larger objects have larger mass than smaller objects but mass ultimately depends on how compact (dense) a substance is.
On Earth, acceleration due to gravity (g) is approximately __________.
1 m/s |
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1 m/s2 |
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9.8 m/s2 |
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6.67 x 10-11 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.
Which of the following statements about drag is false?
the amount of drag depends on the speed of an object |
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drag occurs during movement through a fluid |
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slower objects experience more drag than faster objects |
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the amount of drag depends on the shape of an object |
Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.
| 20.63 lbs. | |
| 6.88 lbs. | |
| 2.29 lbs. | |
| 3.44 lbs. |
To balance this lever the torques on each side of the fulcrum must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:
Rada = Rbdb
where a represents the left side of the fulcrum and b the right, R is resistance (weight) and d is the distance from the fulcrum.Solving for Ra, our missing value, and plugging in our variables yields:
Ra = \( \frac{R_bd_b}{d_a} \) = \( \frac{55 lbs. \times 1 ft.}{8 ft.} \) = \( \frac{55 ft⋅lb}{8 ft.} \) = 6.88 lbs.
For a hydraulic system, pressure applied to the input of the system will increase the pressure in which parts of the system?
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 |
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everywhere in the system |
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.