Ayellow car passes a red car on the highway. from the yellow car's perspective, the red car is moving backward at a speed of 12 km/h. if the red car is moving at 75 km/h relative to the ground, what is the ground speed of the yellow car?

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?