Figure P9.25 shows the essential parts of a hydraulic brake system. The area of the piston in the master cylinder is 1.75 cm2, and that of the piston in the brake cylinder is 6.4 cm2. The coefficient of friction between shoe and wheel drum is 0.50. If the wheel has a radius of 39 cm, determine the frictional torque about the axle when a force of 49 N is exerted on the brake pedal. N·m
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Currents in dc transmission lines can be 100 a or higher. some people are concerned that the electromagnetic fields from such lines near their homes could pose health dangers. for a line that has current 150 a and a height of 8.0 m above the ground, what magnetic field does the line produce at ground level? express your answer in teslas and as a percentage of the earth’s magnetic field, which is 0.50 g. is this value cause for worry?