#$&*
Some of your data will be taken by a computer or with the aid of a computer, and you will not be expected to write down the hundreds or thousands of data points involved in that process, but you should keep a small sample indicative of the results you obtain, and preliminary observations on trends and other aspects of your data which might be relevant to what you are observing.
You should also keep a record of where your data files are located, and you should maintain a secure backup of all your data files. If you lose your data, you might end up having to repeat your experiment.
You might at any point in the course be asked to reproduce information from your lab work. You lab notebook will be the key to being able to do so.
Indicate below, in your own words, the importance of maintaining a good lab notebook.
Maintaining a good notebook is key not only in staying organized in a class like this, but in the “real world” where the ability to easily refer back to previous observations/conclusions is of absolute necessity. Without a neat, organized notebook, labs are essentially pointless, because they are intended to help you continuously build ideas and gather analysis on top of previously made ones.
#$&*
It will be very important in your course that you report data in a way that can be both easily understood and electronically processed by your instructor and by your fellow students.
Report 4 two-digit numbers (e.g., 78 is a two-digit number; you can make up any four such numbers you like), one to each line, with a short note starting at the 5th line indicating how you chose your numbers (the note and the explanation should be brief and uncomplicated; it's not intended to be difficult. Anything you put down will be fine.)
your brief discussion/description/explanation:
22
33
44
55
I chose these numbers because they are all multiples of 11.
************#$&*
`
Next report four 2-digit numbers in one line, separated by commas, and a short note starting at the 2d line briefly explaining how this format is different than the one in your preceding response.
your brief discussion/description/explanation:
12,17,19,20
This format is definitely less organized that the vertically written way before, as one must be very careful to recognize that these are separate numbers. This also makes it especially difficult in high numbers, which are sometimes written with commas (ex. 100,000)
************#$&*
`
Suppose we have a meter stick oriented to that readings run in cm from left to right. Suppose we also have some object sitting at the 15 cm position. Another object at the 25 cm position will be 10 cm to the right of the first object, so the position of the second object relative to the first is +10 cm (remember that increasing numbers go to the right, so + indicates an object to the right of the reference position).
A third object sitting at the 5 cm mark will have a position relative to the first of -10 cm (as we move to the left readings on the meter stick decrease, so the - sign indicates a position to the left of the reference object).
An object with a position relative to the first object of -5 cm will be 5 cm to the left of the reference object, which will place it at the 10 cm mark of the ruler.
Call the position of the first object the reference position. Then an object at +25 cm relative to the reference position will be 25 cm to the right of the 15 cm mar, putting it at the 40 cm mark.
Jot down your answers to the following in your lab notebook. It is suggested that you accompany your answers with a sketch. If you don't yet have a dedicated lab notebook
• What would the position relative to the reference object of an object at the 20 cm mark?
• Where on the ruler would be an object at position -7 cm relative to the reference object?
• If an object is at the 2 cm mark on the ruler, what is its position relative to the reference position?
• What is the position on the ruler of an object located at +35 cm with respect to the reference position?
Place your answers in the first line of the indicated space below, with commas between your answers. Place only numbers and commas in this line.
On the second line specify the meaning of the numbers on the first line, and the units represented by those numbers (the units here are centimeters).
Then give a brief explanation of your understanding of the concept of relative position.
your brief discussion/description/explanation:
+5cm, 8cm from left side, -13cm, 50cm from left side
The 1st and 3rd answers are the distance of the objects relative to the first object, at the 15cm mark. The 2nd and 4th answers are actual distances from the left side of the ruler. All measurements are in cm.
************#$&*
`
Suppose the y positions 5, 12, 21, 37, in cm, occur at respective clock times 2,4,6,8 seconds. A comma-delimited table of y vs. t would then consist of 4 lines with the t value first and the y value second.
Important convention: When we list one quantity vs. the second quantity, it's the second quantity, the one after the 'vs.', that goes in the first column. Remember this.
So the table corresponding to the above information would be
2, 5
4, 12
6, 21
8, 37
Suppose now that temperatures of 80, 60, 50 and 45 deg occur at clock times 3, 10, 24 and 41 minutes.
Report this temperature vs. clock time data in the indicated space below, in comma-delimited format as explained above. Use numbers only--no units. The units will be explained in your additional lines.
Then add a sentence or two starting in the fifth line, which specifies what these number mean: which number is first, which is second, and why; what quantity is belng listed vs. what; and in what units each quantity is being reported.
your brief discussion/description/explanation:
3, 80
10, 60
24, 50
41, 45
The first numbers at the clock times, in minutes, and the second numbers are the temperatures that relate to these specific times, in degrees.
************#$&*
`
Suppose that in a flow experiment depths of 30, 20, 14 and 9 cm occur at clock times of 2, 12, 24 and 36 seconds. List the clock times only in the first line, separated by commas. List the depths only in the the second line, also in comma-delimited format. Starting in the third line, briefly explain what you did.
your brief discussion/description/explanation:
2, 12, 24, 36
30, 20, 14, 9
All of the clock times are in the first row, in order, and all of the depths are in the second row, also in order.
************#$&*
`
Now go into Notepad or another text editor, list the ordered pairs indicating the data just given above, but in tab-delimited format.
You have to go into another program to enter tabs because if you try to enter a tab on the form, it will 'jump' you to the next 'answer box'.
Enter your data so that on the first line you have your first clock time, then a single tab (hit the 'tab' key on your keyboard), followed by the first depth.
Then add a line for each subsequent data point, so that you have reported your information on four lines delimited by tabs.
On the fifth line, specify the units of the data you have given. Starting in the next line give a very brief explanation of what you just did.
Then highlight, copy and paste this data into the form.
your brief discussion/description/explanation:
2 30
12 20
24 14
36 9
s cm
I entered all of the data by typing in the first column of times and then tabbing over to depth. I did this for each pair of 'points'
************#$&*
`
Suppose that the third column of the Timer program shows the numbers 3.7, 4.3, 5.2, 3.9, 4.3. Recall that the third line consists of the time intervals between clicks.
The clock time of the first click would be in the middle column. If necessary, briefly review the TIMER program, or the data you have obtained from that program.
We will define the 'first click' as the one that occurred at the beginning of the 3.7-second interval.
What would be the clock time relative to the first click of each of the four given numbers from the third line?
List these clock times in the first line in comma-delimited format. In the second line indicate the units of the numbers you have placed in the first line, and explain how you obtained the clock times.
your brief discussion/description/explanation:
0.6, 1.5, 0.2, 0.6
These numbers are in the units of seconds. To find them, I simply took the numbers the Timer program displayed and subtracted each by 3.7.
************#$&*
`
Suppose that in a room at temperature 23 C, an experiment reports 50 C, 40 C, 35 C and 31 C. Report these temperatures in Celsius degrees in the first line, using comma-delimited format. In the second line report in the same format the temperatures relative to room temperature. In the third line specify what the units are, that the second-line temperatures are relative to room temperature, and also report the room temperature.
your brief discussion/description/explanation:
50, 40, 35, 31
27, 17, 12, 8
The units are in degrees Celsius. The second row are the temperatures relative to the room temperature of 23 degrees Celsius.
************#$&*
`
Finally, suppose that the temperatures given above occur at clock times 10, 20, 30 and 40 minutes. Report temperature vs. clock time in comma-delimited format, one temperature and one clock time to a line.
Then in a fifth line, report in comma-delimited format the average rate of temperature change with respect to clock time, in degrees Celsius per minute, on each of the three intervals.
Starting at the sixth line state what is reported in your lines, and how you obtained your average rates.
your brief discussion/description/explanation:
10, 50
20, 40
30, 35
40, 31
-7.25 degrees Celsius per minute.
The first numbers are the clock time in minutes and the second numbers at the temperature in degrees Celsius. To find the average rate of temperature change, I looked at each pair to the next and recorded the change in temperature. I added all of these together and divided by 4.
the question asked for the average rate on each of the three intervals. That would be three average rates, not a single average.
It's hard in any case to see how you got -7.25 deg / min.
************#$&*
`
Your instructor is trying to gauge the typical time spent by students on these experiments. Please answer the following question as accurately as you can, understanding that your answer will be used only for the stated purpose and has no bearing on your grades:
Approximately how long did it take you to complete this experiment?
40 minutes
************#$&*
`
You may also include optional comments and/or questions.
************#$&*
"
See if you can clarify your last solution.
#$&*