Chapter 15
#1. A piece of wood with a density of 706 kg/m3 is tied
with a string to the bottom of a water-filled beaker. The wood is
completely immersed, and has a volume of 8.00 x
10-6m3. What is the tension in the
string?
#2. An aneurysm is an abnormal enlargement
of a blood vessel such as the aorta. Suppose that , because of an
aneurysm, the cross-sectional area A1 of the aorta
increases to a value of A2 = 1.7A1. The speed
of the blood (density =1060 kg/m3) through a normal portion of the aorta is
v1 = 0.40 m/s. Assuming that their aorta is horizontal
(the person is lying down), determine the amount by which the
pressure P2 in the enlarged region exceeds the pressure
P1 in the normal region.
#3. Mercury is poured into a tall glass. Ethyl alcohol is then poured
on top of the mercury until the height of the ethyl alcohol itself is
110 cm. The two fluids do not mix, and the air pressure at the top of
the ethyl alcohol is one atmosphere (1.013 x 105 Pa). What
is the pressure at a point that is 7.10 cm below the ethyl alcohol -
mercury interface?
Chapter 16
#4. A grandfather clock is controlled by a swinging brass pendulum
that is 1.3000 m long at a temperature of 20.0oC.
a) What is the length of the pendulum rod when the temperature drops
to 0.0oC?
b) If this is a simple pendulum, does the change in length of the rod
cause the clock to run fast or slow? Explain.
#5. A calorimeter cup is made from 0.15 kg of aluminum and contains
0.20 kg of water. Initially, the water and the cup have a common
temperature of 18.0oC. A 0.040 kg mass of unknown material
is heated to a temperature of 97.0oC and then added to the
water. The temperature of the water, the cup and the unknown material
is 22.0oC after thermal equilibrium is reestablished.
Ignoring the small amount of heat gained by the thermometer, find the
specific heat capacity of the unknown material.
Chapter 17
#6. A tank contains 11.0 g of chlorine gas (Cl2) (assume it is ideal) at a
temperature of 82oC and a pressure of 5.60 x
105 Pa. a) Determine the volume of the tank. b) Later, the
temperature of the tank has dropped to 31oC and, due to a
leak, the pressure has dropped to 3.80 x 105 Pa. How many
grams of chlorine have leaked out of the tank? The atomic mass of
chlorine is 35.453u.
#7. In a container of negligible mass, 0.140 kg of ice initially at
-15.0oC is added to 0.190 kg of water that has a
temperature of 35.0oC. a) If no heat is lost to the
surroundings, what is the final temperature of the system? b) How
much ice is left, if any?
Chapter 18
#8. A system gains 1500 J of heat, while the internal energy of the
system increases by 4500 J and the volume decreases by 0.010
m3. Assume the pressure is constant and find its
value.
#9. Five thousand joules of heat is put into a Carnot engine whose
hot and cold reservoirs have temperatures of 500 K and 200 K,
respectively. How much heat is converted into work?
Answers:
Chapter 15
#1. .0230 N
#2. 55 Pa
#3. 1.19 x 105 Pa
Chapter 16
#4. a. 1.2995 m, b. clock runs fast
#5. 1300 J/kgCo
Chapter 17
#6. a. 8.17 x 10-4 m3, b. 2.3 g
#7. a. 0oC, b. .070 kg of ice left
Chapter 18
#8. 3.0 x 105 Pa
#9. 3000 J