One advantage of using air as the working fluid in a solar collector is ________.
a. that freezing will not be a problem
b. that water heats up faster than air
c. a smaller storage facility can be used
d. that one needs hot water for showers
Question 2
Which type of force would be the equal and opposite force to a gravitational force?
a. gravitational
b. electromagnetic
c. strong
d. weak
e. It could be any one of the above or some combination of them.