LAB 10: ARCHIMEDES, SOLIDS, LIQUIDS (for Monday, August 23)

Physics Lab 10: Archimedes, Solids, and Liquids Name _____________
Monday, August 23, 2010 Dr Dave Menke, Instructor

I Title: Solids and Liquids

II Purpose: To observe the effects of solids in a liquid environment

III Equipment and Supplies:
500-mL beaker, Large clear glass, or similar
Water
A metallic cylindrical weight much denser than water
A pair of tongs
Paper Towels to clean up your mess
Metric Ruler
Paper Clip(s)
Straw
“Sharpie” style pen

IV Procedure
1. Determine the diameter, d, of the beaker or glass in cm. Record.
2. Determine the area, A, of the base of the beaker or glass (A = p r2, where r = ½ d). Record.
3. Determine the height/depth of the beaker or glass, h, in cm. Record.
4. Calculate the maximum volume of the beaker or glass in cm3. Record. [Do this by multiplying the height/depth that you found in #3 (h), with the area of the base of the glass or beaker, A, that you found in #2].
5. Fill beaker about ¾ full with water (measure ¾ h from the bottom of the beaker, record, and mark the outside of the beaker/glass with Sharpie Pen).
6. Be sure that the marked water line is level with the water.
7. Use a straw to remove some of the water, via capillary action (don’t use it to drink the water). This means to lower the straw into the water almost all the way to the bottom, place your finger over the top of the straw, and slowly remove it. (The water should stay in the straw, unless it is defective. DON'T THROW THE WATER AWAY THAT IS IN THE STRAW).
8. Note the new water line. Measure how far the water line dropped in millimeters. Convert to centimeters. Record.
9. Return the water in the straw to the beaker and put away the straw. Make sure the water line is the same as before; if not, then add a few more milliliters of water to make it so.
10. Carefully place ONE paper clip on the water’s surface – if you are good at it, the paper clip will float. How many times did you have to do this to make it work? Record.
11. How many paper clips can you put on the water before it breaks the surface tension? Record.
12. Explain what allows the paper clip(s) to float.
13. Remove the paper clip(s) and put them away. Make sure the water line is back to where you started.
14. Select a metal (lead) weight. Calculate its volume, in cm3. Record. (Do this by measuring the diameter of the base, then get the Area of the base in cm2, then measure the height, and multiply the area times the height.)
15. Slowly place (with tongs) the dense lead weight into the water; note the new water line. Measure how far the water line increased, in millimeters, above the water line. Convert to centimeters. Record.
16. Find the increased volume of the water from the addition of the weight in cm3. Do this by multiplying what you found in #15 with the Area that you found in #2. Record.
17. Compare what you just found in #16 with what you calculated in #14 (they should be the same.) Explain.

V Data & Observations
A. Diameter of the beaker or glass d = ______ centimeters
B. Area of the bottom of the beaker or glass = ___________cm2.
C. Height/depth of the beaker or glass, h = ______ centimeters
D. Volume of the beaker or glass, Vb = ____________ cm3.
E. The distance from the bottom of the beaker/glass to ¾ h = ________ cm.
F. Distance that the water dropped from capillary removal ______ cm
G. Number of attempts to make the paper clip float: _____ times
H. Number of paper clips before breaking surface _______ paper clips
I. Explanation of floating paper clips:
J. Volume of lead weight, Vc = ___________ cm3.
K. Distance that the water increased from submersion of dense weight: ______ cm.
L. Increased volume of the water due to the submersion of the weight: ___________cm3.
M. Comparison between #14 and #16.



VI Results:



VII Error Analysis
A. Qualitative Only
1. Personal
2. Systematic
3. Random
B. Quantitative: NA

VIII Questions
1. Why can the straw hold water, even if the bottom is open and gravity is pulling on it?
2. What can you conclude about denser materials in water?
3. In one paragraph of a few sentences, explain Archimedes' Principle.

END