Date __________
Partners ________________________________________________________
APHY101 – Lab #5 – Properties of Fluids
Equipment
Samples of lead, wood and Styrofoam
Diet and regular soda cans
Double-tray balance
CBL pressure sensor
Large graduated cylinder
Eggs
Procedure
Archimedes’ Principle
A1. Balance equal masses of lead and wood using the double-tray balance. Repeat with lead and
Styrofoam. How do the volumes compare in each case?
How do the densities compare in each case?
A2. Measure the mass of each soda can using the electronic balance. Now place the soda cans
into the bucket of water. Describe what happens.
How does the density of the different kinds of soda compare to the density of tap water?
How do the relative densities relate to the sugar content for each soda?
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Neil E. Miller
3/9/2016
A3. Use the digital balance to determine the egg’s mass. Measure the volume of the egg by
carefully placing the egg into the graduated cylinder and record the change in the level of the
water (1 mL = 1 cm3). Use the mass and volume to find the egg’s density in g/cm3.
Mass of the egg = __________ g
(measured)
Volume of the egg = __________ cm3
Density of an egg = ___________ g/cm3
(measured)
(calculated)
A4. Place the egg carefully in the small beaker of tap water. Now place the egg in the other
beakers containing various amounts of salt in the water.
Which beaker has enough salt to make the egg float? ________
How does the density of the egg compare to that of tap water?
Does the addition of the salt increase or decrease the density of the water? Explain.
Why do some people find it difficult to float in water while others don’t?
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Neil E. Miller
3/9/2016
A5. Why does it sink?
__________ N
1. Weight of the object in the air (mass in kg * acceleration of gravity)
__________ mL
2. Volume of the water in the cylinder
__________ mL
3. Volume of the water in the cylinder when the object is submerged
__________ mL
4. Difference in the volume of the water = volume of the object
__________ N
5. Weight of the object in the water
__________ N
6. Difference in weight of object between air and water
__________ N
7. Weight of water displaced by the object (measured on a balance)
Compare your values for #6 and #7.
Why does the object sink?
Determine the density of your sample in g/cm3 (note: 1mL = 1cm3). What type of metal is the
sample?
Aluminum 2.7
Brass 8.5
Steel 7.8
Copper 9.0
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Neil E. Miller
3/9/2016
Lead 11.3
Zinc 7.1
A6. Why does wood float?
__________ N
1. Weight of the wood in the air (mass in kg * acceleration of gravity)
__________ mL
2. Volume of the water in the cylinder
__________ mL
3. Volume of the water in the cylinder when the wood is floating
__________ mL
4. Difference in the volume of the water
__________ N
5. Weight of water displaced by the wood (measured on a balance)
Compare your values for #1 and #5.
Why does the wood float?
Pressure vs. Volume
B1. The apparatus used includes a Pressure Sensor attached to a large syringe. Record the
pressure from the CBL unit with the syringe set at the 10 mL mark. Now push the plunger in
until you reach to 5 mL mark and record the pressure. Complete the data table below.
V(mL)
P (kPa)
5
7.5
10
12.5
15
17.5
20
B2. Based on your data, by what factor does the pressure change when the volume was halved?
Vi Pf


Vf
Pi
By what factor does the pressure change when the volume was tripled?
Vi Pf


Vf
Pi
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Neil E. Miller
3/9/2016
B3. Make a scatter graph of (x , y) = (V , P). What is the relationship between pressure and
volume of a gas? Explain.
Pressure vs. Temperature
C1. The apparatus includes a Pressure Sensor, CBL unit, thermometer, flask and stopper
assembly. The air in the flask is at room temperature and pressure to start, then the flask is
placed into different large beakers with water at various temperatures. Record the room’s
temperature and the pressure of the air in the flask.
C2. Now place the flask carefully into the beaker of ice water. Hold the flask in the water for 2
minutes or until the pressure stops changing on the CBL unit. Record your values of temperature
and pressure.
C3. Repeat for the warm and hot water. CAUTION – the hot plates and water can burn so
be carefully when holding the flasks. Note: temperature in K = temperature in C + 273
Temperature (K)
Temperature (C)
Pressure (kPa)
Ice water
Room
Warm water
Hot water
C4. Make a scatter graph of (x , y) = (T(K) , P). Explain the relationship between the pressure in
a gas and its temperature based on the speed of the particles.
C5. As you lower the temperature, why should your data eventually reach the origin on your
graph?
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Neil E. Miller
3/9/2016