| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.21 |
| Score | 0% | 64% |
Changes to an object's speed or direction of motion are caused by which of the following?
power |
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work |
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a force |
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kinetic energy |
Force is applied to change an object's speed or direction of motion.
The two heart chambers that pump blood called:
aorta |
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ventricles |
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atria |
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valves |
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.
In the Periodic Table of the Elements, atomic number is equal to which of the following?
number of protons + neutrons in the nucleus |
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number of neutrons in the nucleus |
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number of electrons orbiting the nucleus |
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number of protons in the nucleus |
The Periodic Table of the Elements categorizes elements primarily by the number of protons in their nucleus (atomic number) and secondarily by the characteristics they exhibit.
What is the body's largest artery?
capillary |
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aorta |
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arteriole |
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vena cava |
The aorta is the body's largest artery and receives blood from the pulmonary vein via the left ventricle. From there, blood is circulated through the rest of the body through smaller arteries called arterioles that branch out from the heart. Finally, blood is delivered to bodily tissues through capillaries.
Which of the following is the formula for power?
\(P = \vec{w}t\) |
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\(P = {w \over t}\) |
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\(P = {\vec{w} \over t}\) |
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\(P = w t\) |
Power is the rate at which work is performed or work per unit time: \(P = {w \over t}\) and is measured in watts (W).