| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.25 |
| Score | 0% | 65% |
Changes to an object's speed or direction of motion are caused by which of the following?
power |
|
kinetic energy |
|
work |
|
a force |
Force is applied to change an object's speed or direction of motion.
In the metric system, what prefix represents 10-3?
kilo |
|
centi |
|
mega |
|
milli |
In the metric system, milli is the prefix for 10-3.
212°F is how many °C?
100 |
|
0 |
|
\(135 {5 \over 9}\) |
|
-100 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (212 - 32)\)
\(C° = {5 \over 9} (180) = {{180 \times 5} \over 9}\)
\(C° = {900 \over 9}\)
\(C° = 100\)
Which part of the respiratory system helps protect against infection?
nasal cavity |
|
pharynx |
|
trachea |
|
epiglottis |
After air enters through the nose, it passes through the nasal cavity which filters, moistens, and warms it. Further filtering takes place in the pharynx, which also helps protect against infection, and then in the trachea which is just past the epiglottis, responsible for preventing food from entering the airway.
In the Periodic Table of the Elements, elements in the same column belong to the same:
group |
|
family |
|
atomic number |
|
period |
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.