| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.22 |
| Score | 0% | 64% |
The pitch of the siren of an approaching ambulance changes as it approaches you. This is an example of which of the following?
sound radiation |
|
refraction |
|
reflection |
|
Doppler effect |
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.
The angle of reflection is equal to which the following?
refractive index |
|
angle of incidence |
|
focal point |
|
90° |
The law of reflection specifies how waves, including light waves, bounce off of surfaces. Specifically, the angle of incidence of the approaching wave is equal to the angle of reflection of the reflected wave as measured from a line perpendicular (90°) to the surface.
Menstruation occurs when:
the ovum fails to become fertilized |
|
the zygote is formed |
|
the fetus is formed |
|
the ovum becomes fertilized |
If the ovum fails to become fertilized, the lining of the uterus sloughs off during menstruation. From puberty to menopause, this cycle of menstruation repeats monthly (except during pregnancy).
Stratus clouds are __________clouds characterized by horizontal layering with a broad flat base.
mid-altitude |
|
high-altitude |
|
low-altitude |
|
all-altitude |
Clouds are categorized based on their shape, size, and altitude. Stratus clouds are low-altitude clouds characterized by horizontal layering with a broad flat base. When stratus clouds occur on the ground the result is fog.
Poor balance could indicate an issue with which part of the nervous system?
medulla |
|
cerebellum |
|
cerebrum |
|
spinal cord |
The cerebellum is a large cluster of nerves at the base of the brain that's responsible for balance, movement, and muscle coordination.