| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.25 |
| Score | 0% | 65% |
The pitch of the siren of an approaching ambulance changes as it approaches you. This is an example of which of the following?
reflection |
|
refraction |
|
Doppler effect |
|
sound radiation |
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.
Tough fibrous cords of connective tissue that connect muscles to the skeleton are called:
tendons |
|
cartilage |
|
ligaments |
|
vertebra |
Tough fibrous cords of connective tissue called tendons connect muscles to the skeleton while another type of connective tissue called ligaments connect bones to other bones at joints (elbow, knee, fingers, spinal column).
Which of the following describes how a person's genes express themselves in physical characteristics?
genotype |
|
chromotype |
|
phenotype |
|
DNA |
A person's genotype is their genetic makeup and includes both dominant and recessive alleles. Phenotype is how the genes express themselves in physical characteristics.
Elements in the same group in the Periodic Table of the Elements have the same:
number of electrons |
|
number of electrons in their outer electron shell |
|
number of atomic mass units |
|
number of electron shells |
The columns of the Periodic Table are called groups and all elements in a group have the same number of electrons in their outer electron shell. The group that an element occupies generally determines its chemical properties as the number of outer shell electrons establishes the way it reacts with other elements to form molecules. So, because each element has the same number of electrons in its outer shell, each has similar reactivity.
50°F is how many °C?
10 |
|
-10 |
|
122 |
|
58 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (50 - 32)\)
\(C° = {5 \over 9} (18)\)
\(C° = {90 \over 9}\)
\(C° = 10\)