Lab Primer

 Please note: By themselves, these activities are relatively straightforward. The apparatus you will be using today is deliberately low tech. I am hoping to accomplish the following objectives by causing you to do today's activities: 1. Some of the activities are open ended; I have not laid out any procedure to follow. There are no right or wrong answers; I am simply curious to see how you will answer the questions. 2. Each group will record data from the measurements they make. It is quite likely that the data will not be identical. We need to discuss how we know what data to trust and why. 3. I am curious to see how you work in a partnership; who leads? who follows? Each group should select a principal investigator (PI) who shall be responsible for directing the group in its work today and in the preparation of a lab report. In time and before you graduate, everyone should have a turn as PI. 4. Taking sound data is important, but your good work can be lost if your data are not managed correctly. We are going to use Excel spreadsheet to organize data and facilitate calculations. If you need it, you will be given sufficient instruction in using Excel. 5. A single lab report for your group is due one week from today. Directions for writing this report can be found on the Physics2k2 web site in the Homework Protocols section.

Activities
A. Measure the height (in cm) of each member of your group. Exchange your data with other groups so that you have a measurement for everyone. We will analyze the data with Excelâ later.

B. On the table near my desk are objects labeled "A" and "B". Measure the mass of each using the triple beam balance and the electronic balance. Are the masses reported by each balance the same? Which reading do you trust? Why? Which balance is more accurate? Which is more precise? (These two terms are not interchangeable.)

C.. Using the meter sticks provided, determine the length and width (in meters and fractions thereof, please) of this room. Collect similar data from other groups. We will analyze the data with Excelâ later.

.D. The stairway to the attic makes some angle with the floor. What is the measure if this angle? (Protractors are not very reliable. Try another method.)

E. On a table near my office please find a ball of string and a collection of solid objects tat could be used to make a pendulum. Fashion a pendulum whose length is between .5 m and 2 m. You may suspend the pendulum on one of several screws I have installed for this purpose near the alcove. 1) measure the length, L, of the pendulum (from the point of suspension to the middle of the weight). 2) Using a stop watch provided, measure the time, T, for one complete cycle. Do this enough times to ensure that you are confident of your results. Repeat steps 1 and 2 for four other lengths. What do you conclude about time and pendulum length?

F. There is a large scale in the room. What is your weight in pounds? What is your mass in kilograms? Aside from the different units, what is the difference between mass and weight?

Last edited 01/01/06