4.) Quantitative: notice the root word 'quantity', which is a certain percentage of something.
a.) Quantitative, since it represents a certain percentage. The weight before the camp could also be written as an improper fraction.
b.) This is also quantitative because it can be written as a ratio
, which can also be written as a fraction
or percentage.
c.) This is qualitative. Joan has a higher percentage than Emile.
d.) Qualitative. It judges the quality of something instead of amount. To make it quantitative requires a fraction of percentage. In this case, maybe you could add how he can run y miles every x seconds.
5.)
a.)This depends on whether or not the air is moving. If the classroom's AC is on, or the window is open, then the correct unit to use is CFM (cubic feet per minute). If not, the common unit is milliliters, but must also include temperature and air pressure as well as the volume of the room.
b.) Simply calculate the volume of the can using inches cubed, since volume is the measure of how much space an object takes up.
c.) The unit would be 
. If 
, then simply multiply your density by your mass.
d.) I personally would use centimeters. Inches would work too, but centimeters would be much more accurate.
e.) Use the same formula for c.), which means kilograms per cubic foot.
Hope this helped.
is the variation of momentum, F is the intensity of the force and 
is the time of application of the force. 
, we can find the variation of momentum:
and 
are the final and initial momentum. But the ball is initially at rest, so the initial momentum is zero, and
