Writing Up Your Lab For Mr Brügge
Every lab will have the following:
1. A Page One which includes a procedure, conclusion, and small sketch.
2. Very often you will be required to put your data into a graph. All graphs will be generated on a spreadsheet program.
Below is a
sample lab written by an eighth grader. This will give you a good
idea of what a well-written lab looks like.
Experimental Speed of Two Types of Rockets
In this lab we were trying to figure out the speed of two rockets. Which one is faster? Using data and other information that I learned in class I will try to explain just that, what I learned (and possibly some helpful tips for shooting those tricky rockets!!!).
Materials
o Big rocket (about mid-thigh high)
o Little rocket (about knee high)
o Stop-watch
o Meter stick
o Pencil and paper to record your data
Procedure
Before we went outside to begin the trails, our group had to decide what size of rocket we wanted to use first. We chose to start with the big rocket first, which was about knee-high on me. Because we were lucky enough to have three people in our group, we all took turns doing the following things: shooting the rocket (my personal favorite), timing the rocket's flight, and measuring the distance that the rocket went. Once we got outside we chose a nice shady spot where the wind seemed to be blowing in a direction that would carry the rocket further. After we had each gotten a hand of shooting the rocket and working the stopwatch, we began our first trail. We decided to use the tip of the rocket as our measuring point and the beginning of the sidewalk as a starting point when we began measuring. The person who was timing counted down 3...2...1 and then the person shooting the rocket shot the rocke...BOOM! After the rocket had landed softly in the grass, the person in our group who had the meter stick started measuring from the point where the rocket had landed to the beginning of the sidewalk. After a few failed flights, we seemed to get an idea of what made the rocket travel farther and in some cases faster. Some of these factors included slightly arching the rocket right before "take-off", pushing the end of the rocket with more force, and waiting for the wind to either stop or blow in the direction desired. After each trial we carefully recorded our data in our notebook and re-did any trials where the data was extremely wrong or where an error had obviously been made. Our data didn't show a very constant patter of meters/seconds. Many things might be at blame here. Some of these include:
o The direction and speed at which the wind was blowing.
o The person who was shooting the rocket may have shot it differently than others in the group.
o The stopwatch-sometimes the person operating it started it too early, too late, or vise-versus for the ending.
o The force that the rocket was shot may also have an effect.
o The location or point at which the rocket was shot could have affected the results. Sometimes we may have moved spots (especially the transition from the first day to the second.)
o The landing point of the rocket was probably somewhat different to what was actually written down. Sometimes when the rocket landed it took a few bounce and ended up farther that where it actually landed.
With all these variables to consider, you question how accurate our answers were. On the second day of trails we repeated all of the instructions above only this time using the smaller of the two rockets. The data for the small rocket also showed no pattern just as the data for the large one hadn't. When we had completed all the trails we were left with a total of 5 trails for the big rocket and 6 for the small one.
Conclusion
As I was explaining in my procedure I had 5 trails for the big rocket and 6 for the small one. I found one outlier for my set of data, which was 11.2 m/s (meters/seconds) for the big rocket. Then I found the average m/s of both rockets. For the big rocket I found an average of 7.4 m/s and for the small rocket I found an average of 5.2 m/s. These two averages would lead you to believe that the larger rocket travels farther and faster, but let's take a minute to think about this. First, considering all the variables that I stated in my procedure that might have affected the data and the fact that the entire flight was not at a steady speed of 7.4 m/s or 5.2 m/s you can't really believe that it's completely true. I learned in class that the initial speed of the rocket is probably at least double of the average. Think about it, you can clearly tell that the rocket is going much faster when it leaves than when it lands. So, the average is just the starting and ending of the flight combined, because the two are very different. I really do believe that one rocket is not any faster than the other. At this point we are in no position to be making guesses. A total 10 trials is not enough to make an educated guess. After we have completed more trials and really examined the data we could decide from there.
Below is what a typical graph should look like:
