When Susan checks her barometer tomorrow, which change is she most likely to note?

Susan is studying air pressure and makes a simple mercury barometer as shown below. She knows that air exerts pressure. More pressure on the surface of the mercury in the bowl will cause the mercury level to rise. Less pressure will cause the mercury to fall. High barometric pressure is often associated with fair weather, and low barometric pressure is associated with rain.

Susan is enjoying a bright, sunny day when she hears a local weather forecaster predict rain for tomorrow.

When Susan checks her barometer tomorrow, which change is she most likely to note?
A . totally fill the tube
B . have risen by about 5%
C . have risen by more than 10%
D . have fallen
E . remain unchanged

View Answer

Answer: D