Name ______Name ______Date ______Class Period _____ Date ______Class Period _____ Instructor ______Lab Period ______Instructor ______Lab Period ______5 points Settling Rates DATA TABLES

PARTICLE SIZE VS. SETTLING TIME 3 points each 4 mm 7 mm 12 mm Trial 1

Trial 2

DENSITY VS. SETTLING TIME 3 points each Density Trial 1 Trial 2 Clay 1.9 g/ml

Marble 3.4 g/ml

PARTICLE SHAPE VS. SETTLING TIME 3 points each Trial 1 Trial 2 Ball

Small Disc (dime size) Large Disc (quarter size) Graphs 4 points each

S S S E E E T R T R T R T A T A T A L T L T L T I E I E I E N N N G G G

flat round Particle Size Density Roundness (Shape)

S S S E E E T T T T T T T I T I T I L M L M L M I E I E I E N N N G G G

flat round Particle Size Density Roundness (Shape) QUESTIONS: 3 points each. Use complete sentences. Do not use personal pronouns (we, they, us, I, etc.) 1.

2.

3.

4.

5. A B C D

6. A B C D

7. A B C D Lab # 25 Settling Rates

INTRODUCTION: Please read this as it contains information required to perform the lab and material that may be tested.

Rock and soil material carried by streams and rivers is eventually deposited in water that is relatively quiet. Unfortunately, direct observation of the depositional process is not usually possible. In this lab, you will study some factors that can influence the way materials settle to the bottom in quiet water.

PROCEDURE:

PARTICLE SIZE Set up the plastic column as instructed by the teacher. Time the settling rate of each of three different particle sizes; 4mm, 7mm, 12mm. One person should drop the particles, one at a time, into the plastic column. The other person will time the particle, starting the stopwatch at the top piece of tape and stopping the watch at the bottom piece of tape. Two trials should be run for each particle size.

DENSITY Make eight clay balls, the size of a marble. Use the marble for comparison. Six clay balls will be used for the next part of the experiment. It is important to get the size as close as possible. Time the marbles and a clay balls. Clay has a density of 1.9 g/ml and the marble has a density of 3.4 g/ml.

SHAPE OR ROUNDNESS Use the remaining clay balls to test particle shape. Leave two clay balls spherical. Flatten two clay balls to the diameter of a dime and the other two to the diameter of a quarter. Time the settling rate of each particle.

GRAPH Draw general trend lines for the relationships shown. You don’t need to use exact numbers. Remember that rate and time are opposites. Something with a high rate will have a low time and vice-versa. QUESTION: Answer using complete sentences. Do not use personal pronouns. 1. State the relationship between particle size and settling rate.

2. State the relationship between density of a particle and settling rate.

3. State the relationship between particle shape and settling rate.

4. If all three particle sizes used in this lab were dropped at the same time, how would the particles settle?

5. A glass sphere and a lead sphere have the same volume. Each sphere is dropped into a container of water. Which statement best explains why the lead sphere settles faster? A) The glass sphere has a smoother surface. B) The lead sphere has a higher density. C) The lead sphere takes up less space. D) The glass sphere has more area.

6. A handful of material is dropped into a tube. All of the material has the same density and the particle shapes are roughly the same. In which order would the particles settle from the bottom of the tube upward. A) coarse on the bottom, then medium, then fine B) coarse on the bottom, then fine, then medium C) fine on the bottom, then medium, then coarse D) fine on the bottom, then coarse, then medium

7. If all the particles below have the same mass and density, which particle will settle fastest in quiet water?