Open a can of roofing cement. This is an asphalt-based glue that will adhere to almost anything. Dip a 2-inch wide brush into the cement and lay a 2-inch line of cement from end to end of the roof, starting at the bottom edge of the building. Be liberal with the cement as you brush it along the roof edge.
In a direct current (DC) circuit, voltage or current is simple to define, but in an alternating current (AC) circuit, the definition is more complicated, and can be done in several ways. Root-mean-square (rms) refersto the most common mathematical method of defining the effective voltage or current of an AC wave. To determine rms value, three mathematical operations are carried out onthe function representing the AC waveform: (1) The square of the waveform function (usually a sine wave) is determined.
Explaining rms voltage and current. There are many ways of explaining root mean square (rms) voltage and current at different levels of complexity, to advanced level students. 1 For the simplest level, say that you sample the current (or potential difference) at tiny intervals of time. Square each value, add up the squares (which are all positive) and divide by the number of samples to find the average square or mean square. Then take the square root of that. This is the 'root mean square' (rms) average value.