1. (20 points). Suppose you are designing a simple barometer (see Figure 1)

that must be able to measure 1 atm of pressure at 25 °C. The barometer

will be distributed via Amazon, and as a result the height of the tube

must not exceed 1 m. You have to choose a liquid for the barometer from

amongst the following options: water, glycerin, mercury, and ammonia.

(a) Which liquid (or liquids) can be used in the barometer?

(b) Now assume that the barometer tube has a circular cross section and

a sufficiently large height for each fluid. Suppose you double the

diameter of the cross section, fill the tube with each liquid (one at a

time) and invert it to again create a barometer. What happens to

the height of each liquid in the tube relative to what you found in

part (a)?

Patm

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Figure 1: Simple Barometer.

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