To calculate the mechanical resistance of a generator, it's essential to understand that this resistance varies with the electrical load. In an ideal generator with no load, mechanical resistance is zero. However, when powering devices, the input work remains constant based on the power demand. According to the law of conservation of energy, the power required from the generator must equal the power consumed by the load, plus an additional 40% to account for losses due to friction and heat. For practical calculations, especially with hand-crank generators, the force needed can be derived from the formula: force equals the power in watts multiplied by the time taken to complete one crank, divided by the circular distance of the crank's rotation. This calculation provides the force in Newtons, which can be converted to pounds by dividing by 4.4.
