First, let's make sense of the Volume equation for a cylinder. This shape is a tube, flat on two ends like a toilet paper roll (with ends) or a drum. If you imagine this shape as a stack of horizontally placed circles, you can see that the equation is simply the area of a circle (A=Πr2) multiplied by the height of the cylinder (i.e. continuous number of stacked circles with area A.)
The units of volume will always be "cubed" or to the third power, as it is 3-dimensional. The units of area are "squared," or to the second power, since they are 2-dimensional.
SO, by plugging in the numbers we know, you get the following:
Now, youre NOT DONE
Remember the question requested the answer in mL, and we have a volume in meters cubed. Luckily the metric system is easy, and 1m3=1,000L = 1,000,000mL.
So, to get your final answer, you will multiply your volume by the conversion factor, which is 1,000,000mL/1m3, which actually equals 1.
The m3 in the numerator cancels the m3 in the denominator, leaving you with an answer in mL.
Be sure to logically check your answer!
A cylinder thats 11.2cm in diameter and 5.6cm tall would hold about half of a liter, can you visualize this?