| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.45 |
| Score | 0% | 69% |
The pitch of the siren of an approaching ambulance changes as it approaches you. This is an example of which of the following?
Doppler effect |
|
sound radiation |
|
refraction |
|
reflection |
The Doppler effect occurs when the source or listener (or both) of sound waves is moving. If they're moving closer together, the listener perceives the sound with a higher pitch and, when they're moving apart, the listener perceives the sound with a lower pitch.
During digestion, after proteins are broken down where does the undigested food go next?
large intestine |
|
stomach |
|
small intestine |
|
esophagus |
Food is mixed with gastric acid and pepsin in the stomach to help break down protein.
The brain and spinal cord make up the __________ nervous system.
autonomic |
|
somatic |
|
peripheral |
|
central |
The nervous system consists of the brain and spinal cord (central nervous system) and the peripheral nervous system which is the network of nerve cells (neurons) that collect and distribute signals from the central nervous system throughout the body.
50°F is how many °C?
-10 |
|
58 |
|
122 |
|
10 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (50 - 32)\)
\(C° = {5 \over 9} (18)\)
\(C° = {90 \over 9}\)
\(C° = 10\)
A transition zone between two air masses is called:
boundary |
|
fog |
|
thunderstorm |
|
front |
An air mass is a large body of air that has similar moisture (density) and temperature characteristics. A front is a transition zone between two air masses.