If a radiographer receives an exposure of 0.05 millisievert (msv) at a distance of 1.5 feet from the tube of a portable x-ray unit, what will the exposure be at a distance of 6 feet from the tube?

0.003125 msv

Explanation:

= Initial Exposure = 0.05 msv

= Final Exposure

= Initial distance = 1.5 ft

= Final distance = 6 ft

Exposure is inversely related to the distance squared (inverse square law)

So,

The exposure at the given distance is 0.003125 msv

two jet streams that directly affect the formation of weather in the continental part are a polar jet and a subtropical jet. they are responsible for the transportation of weather systems, which directly affect people. the polar front is the boundary between cold air from the north pole and warmer equatorial air. both the polar jet and the subtropical jet blow from the west to the east, and follow the boundary between cold and warm air.

the strongest jet streams are polar jets, while subtropical jets are somewhat weaker.

the right answer is c. the polar jet stream is generaly stronger than the subtropical jet stream.