1. . Air is trapped above liquid ethyl alcohol in a rigid container, as shown in this
figure. If the air pressure above the liquid is 1.10 atm, determine the pressure
inside a bubble 4.0 m below-the surface of the liquid.
Describe the acceleration of the bubble. (Assume there is negligible drag.)
PHYS 101, Chapter 9 Homework

2. 2. Blaise Pascal duplicated Torricelli's barometer using a red Bordeaux wine of
density 984 kg/m3 as the working liquid (as in this figure). What was the height h
of the wine column for normal atmospheric pressure? Would you expect the
vacuum above the column to be as good as for mercury?
PHYS 101, Chapter 9 Homework

3. 3. A solid wooden cube, 30.0 cm on each edge, can be totally submerged in water
if it is pushed downward with a force of 54.0 N. What is the density of the wood?
PHYS 101, Chapter 9 Homework

4. 4. A liquid (ρ = 1.65 g/cm3) flows through two horizontal sections of tubing joined
end to end. In the first section, the cross-sectional area is 10.0 cm2, the flow speed
is 275 cm/s, and the pressure is 1.20x105 Pa. In the second section, the
cross-sectional area is 2.50 cm2. Calculate the smaller section's (a) flow speed
and (b) pressure.
PHYS 101, Chapter 9 Homework

5. 5. A rectangular boat is 4 m long and 1 m wide. It has a mass of 120 kg. To what
depth is the boat submerged (ie. where is its waterline?)
PHYS 101, Chapter 9 Homework

6. 6. A piston of cross-sectional area "a" is used in a hydraulic press to exert a small
force of magnitude "f" on the enclosed liquid. A connecting pipe leads to a larger
piston of cross-sectional area A. If the piston diameters are 3.80 cm and 53.0 cm,
what force on the small piston will balance a 20.0 kN force on the large piston?
PHYS 101, Chapter 9 Homework

7. For safety in climbing, a mountaineer uses a nylon rope that is 50 m long and
1.0 cm in diameter. When supporting a 90-kg climber, the rope elongates 1.6 m.
Find its Young's modulus.
PHYS 101, Chapter 9 Homework

8. 8. A person happens to step on it at the very edge of the opening of the hose and
decreases its internal diameter by a factor of 9. a) What was the water flow rate in
the hose prior to the person stepping on it? b) What is the flow rate of water after
the person steps on it?
PHYS 101, Chapter 9 Homework