| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.19 |
| Score | 0% | 64% |
Which of the following does not represent the freezing point of water?
0°C |
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32°F |
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0°F |
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273K |
The Fahrenheit scale fixes the freezing point of water at 32°F, the Celsuis scale at 0°C, and the Kelvin scale at 273K.
Acceleration is the rate of change of velocity per unit of time. Which of these is the formula for acceleration?
\(\vec{a} = { \Delta \vec{v} \over t }\) |
|
\(\vec{a} = { \vec{v} \over t }\) |
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\(\vec{a} = { t \over \Delta \vec{v} }\) |
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\(\vec{a} = \Delta \vec{v} t \) |
Acceleration is the rate of change of velocity per unit of time. In physics, the delta symbol (\(\Delta\)) represents change so the formula for acceleration becomes \(\vec{a} = { \Delta \vec{v} \over t }\)
The energy posessed by a ball on the window ledge of a tall building is an example of what kind of energy?
kinetic |
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inherent |
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potential |
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gravitational |
Kinetic energy is the energy posessed by a moving object. Potential energy is stored energy in a stationary object based on its location, position, shape, or state.
Which of the following is a decomposer?
mosquito |
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ferret |
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pine tree |
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fungi |
Decomposers (saprotrophs) are organisms such as bacteria and fungi that break down the organic matter in the dead bodies of plants and animals into simple nutrients.
Which of the following would be used in eye glasses to correct nearsightedness?
concave mirror |
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convex mirror |
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convex lens |
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concave lens |
Unlike curved mirrors that operate on the principle of reflection, lenses utilize refraction. A convex lens is thicker in the middle than on the edges and converges light while a concave lens is thicker on the edges than in the middle and diffuses light. A common use for curved lenses is in eye glasses where a convex lens is used to correct farsightedness and a concave lens is used to correct nearsightedness.