| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.27 |
| Score | 0% | 65% |
Which of the following is the formula for power?
\(P = {w \over t}\) |
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\(P = w t\) |
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\(P = {\vec{w} \over t}\) |
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\(P = \vec{w}t\) |
Power is the rate at which work is performed or work per unit time: \(P = {w \over t}\) and is measured in watts (W).
When light travels between two substances it bends. This is called:
refraction |
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conduction |
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reflection |
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convection |
Because different materials have different refractive indices, light changes speed when passing from one material to another. This causes the light to bend (refraction) at an angle that depends on the change in refractive index between the materials. The greater the difference, the higher the angle of refraction.
A human heart consists of how many chambers?
8 |
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4 |
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2 |
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1 |
The heart is the organ that drives the circulatory system. In humans, it consists of four chambers with two that collect blood called atria and two that pump blood called ventricles. The heart's valves prevent blood pumped out of the ventricles from flowing back into the heart.
Water coming to a boil on a stove, ice melting, and steam from a cup of coffee are all examples of which of the following?
conduction |
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convection |
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radiation |
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reflection |
Convection is the transfer of heat by the circulation or movement of the heated parts of a liquid or gas.
Which of these does not contain oxygenated blood?
aorta |
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right atrium |
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pulmonary vein |
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left ventricle |
To provide oxygen to the body, blood flows through the heart in a path formed by the right atrium → right ventricle → lungs → left atrium → left ventricle → body. When blood enters the right side of the heart it is deoxygenated. It enters the left side of the heart oxygenated after traveling to the lungs.