The portable lighting equipment for a mine is located away from its dc supply source needing 100 metres of connecting wire. The lighting equipment can be considered as a purely resistive load. The power lost in the connecting wire is 7% of the power supplied by the dc supply source. If this lighting equipment needs to be moved further away from the same dc supply source and now needs 200 metres of connecting wire (you can assume that the wire of the same material and cross-section as before is being used), then power lost in the connecting wire as a percentage of the power supplied by the de supply source (computed to one decimal place) now is given by (Note: do not include units in your answer, e. g.

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg.m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?