| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.01 |
| Score | 0% | 60% |
| 24.38 lbs. | |
| 6.09 lbs. | |
| 8.13 lbs. | |
| 48.75 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 = \( \frac{R_bd_b}{d_a} \) = \( \frac{65 lbs. \times 3 ft.}{8 ft.} \) = \( \frac{195 ft⋅lb}{8 ft.} \) = 24.38 lbs.
| 37.5 lbs. | |
| 300 lbs. | |
| 0 lbs. | |
| 75 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 Rb, our missing value, and plugging in our variables yields:
Rb = \( \frac{R_ad_a}{d_b} \) = \( \frac{50 lbs. \times 3 ft.}{2 ft.} \) = \( \frac{150 ft⋅lb}{2 ft.} \) = 75 lbs.
Connected gears of different numbers of teeth are used together to change which of the following charasteristics of the input force?
energy |
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rotational direction |
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force |
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torque |
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.
For any given surface, the coefficient of static friction is ___________ the coefficient of kinetic friction.
equal to |
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opposite |
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higher than |
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lower than |
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).
Boyle's law defines the relationship between pressure and volume as:
\(\frac{P_1}{P_2} = {V_1}{V_2}\) |
|
\(\frac{P_1}{P_2} = \frac{V_1}{V_2}\) |
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\({P_1}{P_2} = {V_1}{V_2}\) |
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\(\frac{P_1}{P_2} = \frac{V_2}{V_1}\) |
Boyle's law states that "for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional". Expressed as a formula, that's \(\frac{P_1}{P_2} = \frac{V_2}{V_1}\)