Scalar quantities have only a magnitude. Vector quantities are those such as displacement, velocity, acceleration. The first vector is drawn, then the second from the end of the first, and so on. When you have a straight line which goes through the origin, the unit on the vertical axis is directly proportional to that on the horizontal axis. If c is not zero, then they are not directly proportional.
Period is the time required to complete one cycle ex.
Uncertainties cause uncertainty bard, errors usually result in the particular piece of data being discarded. Systematic errors are those built into the equipment. Record uncertainty along with data. By using graphs we can obtain a line of best fit which wits within all the uncertainties. When adding or subtracting, the uncertainty is the sum of the absolute uncertainties for each term.