In extremely large forests, it is not cost-effective to position forest rangers in towers or to use small aircraft to continua
lly watch for fires. Since lightning is a frequent cause of fire, lightning detectors are now commonly used instead. These devices not only give a bearing on the location but also measure the intensity of the lightning. A detector at point Q is situated 11 miles west of a central fire station at point R. The bearing from Q to where lightning hits due south of R is S37.3°E. How far is the hit from point R?
First of all, we need to calculate the equivalent resistance of the circuit. The three resistors are connected in parallel, so their equivalent resistance is given by:
And now we can use Ohm's law to find the current in the circuit: