Conversions of Units, Estimates, and Order of Magnitude Calculations: The Physics Lecture Series Chapter 1 Sections 4 and 5.
Hello internet, and welcome to the Algebra Lecture Series from The Science of Life. This entry is focusing on conversion of units that you'll see in Physics, Chemistry, Biology, and all of science. Unit Conversion The previous Physics section allows us a mechanism to convert from one unit to another unit of the same type. To do this, we take advantage of the equivalence between two values, and multiply with what is effectively equivalent to one. For example, notice that 1hr=60min. If we divide both sides by 1hr, we get $\frac{1hr}{1hr}=\frac{60min}{1hr}$. In all of science, units such as seconds, meters, and kilograms can be canceled if in a quotient or squared if multiplied together, much like variables. With that in mind, notice that on the left hand side, the hours cancel and the ones cancel, so that we have $1=\frac{60min}{hr.}, which makes sense since there are 60 minutes per hour. This general concept applies to all conversion facto...