The minimum ignition energy tor most hydrocarbon mixtures is 0-25 mJ, the static spark produced by the human body is can be 10* 151 [ref]. If we assume energyr of an electrical ow can be calculated by multiplying the power times the duration, i.e. combining Ohms law and equations for electrical power: If we assume that for the Van de Graft generator, the voltage is 200,000, the duration of the spark is 300 nanoseconds (0.3m). Esec), and the resistance of air is 1.3x1015 ohmsr'm, the energy in the spark created by the Van de Graff generator can be estimated