Water at a gauge pressure of 3.8 atm at street level flows into an office building at a speed of 0.65 m/s through a pipe 5.6 cm in diameter. the pipe tapers down to 2.6 cm in diameter by the top floor, 20 m above (fig. 10-53), where the faucet has been left open. calculate the flow velocity and the gauge pressure in such a pipe on the top floor. assume no branch pipes and ignore viscosity.

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?