ib physics shariq particle lab

8/7/2019 IB Physics Shariq Particle Lab

1/5

Shariq KhanIB Physics HL 1

Particles in a Canister Lab

Variables:

Independent Variable: The independent variable is the type of particle in thecanister.Dependent Variable: The dependent variable is the mass of the canister and theparticles which are in it. This is the variable which will be dependent on theindependent variable.Controlled Variables: instruments used, mass of canister, mass of particle, scaleused, environmental conditions, (within each set: type of particle used)

Purpose:In this lab we were given sets of canisters, each holding different masses insidethem. We knew that these were filled with different numbers of the same particle.

There were four different sets of canisters. The purpose of this lab is to 1) find the

number of particles inside of each canister, 2) to find the mass of the empty plasticcanister, and 3) to find the mass of a single particle. I will be doing this by analyzinga graph of the masses of the canisters arranged by set.

Procedure:1. Find the mass of each canister2. Analyze to fulfill the above Purpose statement. The method of analysis will beexplained in the conclusion section.

Safety:There are no safety concerns in this lab.

Materials:1. Pre-made canisters with different numbers of the same particle arranged into

sets of canisters with the same particle2. Scale3. Loggerpro is helpful, but unnecessary

Observations:The appearance of each canister looked essentially the same. This was an essentialpart of the lab- that we didnt know its composition. The canisters felt differentweights because of their different masses. When shaken, there was a noise whichmade it seem like there was more than one particle inside of them, but it didntseem like very small particles such as beads.

Data and Calculations:

Mass (0.05 g) of Canisters with Particles

Canister Omega Phi Delta Gamma

1 67.6 g 71.9 g 93.8 g 67.9 g

2 67.5 g 58.9 g 82.2 g 60.6 g


2/5

3 54.4 g 58.8 g 71.4 g 54.0 g

4 53.8 g 52.3 g 71.2 g 47.3 g

5 47.2 g 46.0 g 61.5 g 40.7 g6 45.7 g 49.8 g 40.2 g

7 45.6 g 49.6 g

8 39.2 g

9 32.7 g

Difference in Mass (0.05 g) between Canisters


Between 1 and 2 .1* 13.0 11.6 7.3

Between 2 and 3 13.3 .1* 10.8 6.6

Between 3 and 4 .6* 6.5 .2* 6.7

Between 4 and 5 6.6 6.3 9.7 6.6

Between 5 and 6 .3* 11.7 .5*

Between 6 and 7 .1* .2*

Between 7 and 8 6.4

Between 8 and 9 6.4

To find the average mass of a particle, I had to make the assumption that, forexample in Omega, 6.6 g is equal to about one particle, and that 13.3 g is equal toabout 2 particles. In Phi, I estimated that 6.4 g is about 1 particle, and 13.0 g isabout 2 particles. In Delta, I assumed that 11.0 g is about one particle. In Gamma, I

assumed that 7.0 g is about 1 particle. From this I found the actual average mass ofa particle in a canister. For the mass differences marked with an asterisk, I assumedthat the mass difference was actually zero.

Difference in Number of Particles n between Canisters


Between 1 and 2 0 2n n n


3/5

Between 2 and 3 2n 0 n n

Between 3 and 4 0 n 0 n

Between 4 and 5 n n n nBetween 5 and 6 0 n 0

Between 6 and 7 0 0

Between 7 and 8 n

Between 8 and 9 n

Average Mass (0.05 g) of Particles n of Canisters

Omega Phi Delta Gamma

(13.3+6.6)/3=

6.6 g

(13.0+6.5+6.3+6.4+6.4

)/6=6.4 g

(11.6+10.8+9.7+11.7)/

4=11.0 g

(7.3+6.6+6.7+6.6)/

4=6.8 g

To find the mass of the canister and to find the number of particles per container,we must subtract the mass of the particles in each canister. To do this, we subtractin whole number multiples until we arrive at a reasonable number for the mass ofthe container. For example, in Canister Omega-1:67.6 g-6.6-6.6-6.6-6.6-6.6-6.6-6.6-6.6-6.6=67.6g -(9*6.6)=8.2 gIf we had subtracted 6.6 another time, we would have had a mass of 1.6 for themass of the canister, which is unreasonably small. The whole number multiple

which we subtracted by is the number of particles! This method was used for allcanisters.

Number of Particles per Canister


1 9 10 8 9

2 9 8 7 8

3 7 8 6 7

4 7 7 6 6

5 6 6 5 5

6 6 4 5

7 6 4


4/5

8 5

9 5

Mass (0.05 g) of Empty Canister

Omega Phi Delta Gamma

8.2 g 7.1 g 5.6 g 6.7 g

Conclusion:The process to get our final answers was relatively simple and full of assumptions,but it was the best way that I could think of to go about this problem. Once I had themasses of the canisters with the particles inside, I arranged the masses fromgreatest to smallest to see if there was any noticeable pattern. I then graphed thedata. The data, when graphed, seemed to show that whenever the mass fell, it wasby about the same increment, or multiples of that increment. Going off of thispattern, I then decided to subtract each from the next largest to see if thedifference between the masses truly was the same. I found that the massdifferences were not the same, but they were usually very close to the same orwere close to whole number multiples of a mass. Just by looking at the data, it wasvery easy to see that, for example in the Omega set, one mass difference, 13.3 g,was about twice the other mass difference of 6.5 g. This made me believe that themass difference of 6.5 g was the addition or subtraction of one particle, while themass difference of 13.3 g was the addition or subtraction of 2 particles. I assumedthat the differences between canisters which were less than 1 were insignificantand were due to uncertainties or to slight differences in the composition of thecanister, for example, the amount of tape put on it. Next, I used the assumptionthat, for example in the Omega set, 13.3 g was 2 particles and 6.6 g was oneparticle to find the average mass of a particle. I did this for each set. This processworked very well, with the exception of the delta canister set. There was no veryclear pattern to their mass differences which would say exactly how many particleswere added or lost. The range between the mass differences was from 9.7 to 11.7, adifference of 2 g. I assumed then that each mass difference was due to thedifference of one particle. I will talk about this assumption more in the evaluation. Ifound that the average mass for a single particle for Omega, Phi, Delta, and Gammawas 6.6 g, 6.4. g, 11.0 g, and 6.8 g, respectively. This leads me to believe that theparticle was identical in the Omega, Phi, and Gamma sets, but this is just aninference. Using the assumption that all of the mass difference was due todifferences in the number of particles, I decided that I could find the mass of thecanister by subtracting the mass of the full canister by that of the particles. To dothis, I subtracted whole number multiples of the particle mass from the full canistermass until I was left with a mass which seemed reasonable for the mass of thecanister. In all the cases, I could have subtracted enough to have the excess massbe less than 2 g. I decided that 2 g is probably too small to be the mass of thecanister, so I subtracted one less from the full canister mass to get a reasonablemass of the empty canister. The mass of the canister should be about the same for


5/5

each one of the sets, because we knew that it didnt change much. The masses forthe empty canister for Omega, Phi, Delta, and Gamma, were 8.2 g, 7.1 g, 5.6 g, and6.7 g, respectively. The number of particles inside of each canister is listed in atable in the Data and Calculations section. All of the masses in this section haveuncertainties of +/- .05 grams.

Evaluation:Our task was to find the mass of an empty canister, the number of particles insideof a canister, and the mass of a single particle, given only the mass of a solidobject. Naturally, to complete this task, we must make many assumptions. The firstassumption was related to the mass differences. When I looked at the massdifferences, I assumed that they were whole number multiples of each other, andthat the differences which negated this, for example small differences like .1 g or .2g were due to systematic errors or due to some other factor besides the number ofparticles. If I used this assumption, it was easy to find the average mass of aparticle by set. To do this I also assumed that the large differences in mass (thosebesides the .1 g or .2 g differences) were due only to the difference in number ofparticles. In reality, there is no reason why there should only be particles inside of

the canisters, there may have been a mixture of other substances and particles.The Delta canister set was tricky. The differences between the substantial massdifferences was as much as 2 g. Because the mass differences were as high as 11.7to 9.7 g, I assumed that the 2 g difference wasnt due to the addition of a particle. Iassumed this because all of the other canisters had particle differences of at most 2particles. If I said that the 2 g mass difference was because of a difference in thenumber of particles, which would mean that there was a difference of 5+ particlesbetween each canister! Also, if I had used the 2 g difference as being because ofparticle differences, it would call in to question why I disregarded the very small .1 gand .2 g mass differences. It is possible that the mass of a particle was about .1 g,and the particle difference between canisters was as much as 60 particles, butlooking at the data, I dont think that this is probable, so I decided to treat all of the

range of 9.7 to 11.7 mass differences as being due to the difference in the numberof particles of a mass approximately equal to 11.0 g. The next thing which Iassumed was that the mass of a canister was more than 3 grams. When I wassubtracting in whole number multiples, I could subtract until I was left with atheoretical canister mass of .1 to 3 grams. I didnt think that this was feasible, so Isubtracted one less particle to get the actual canister mass. One way to improvethis lab would be to of course decrease the number of assumptions one has to maketo reach the final answer. This could be done by just stating that all the massdifference is due to particles, but small mass differences less than 2 grams are dueto other factors. Another important factor is the amount of tape which is on thecanisters; it can throw off the mass differences. If I had not graphed the data, itwould have been much harder to see the pattern in these mass differences becauseof the small differences due to factors like amount of tape. Another way to improvethis lab would be to use larger objects. This would cause the incidental differencesin mass due to things like tape or other small factors to be obviously insignificantcompared to the mass of a particle. The accuracy of the scale was not a bigproblem because it went to the tenth of a gram, which is probably good enough. Allof the masses from the experiment mentioned in this section have uncertainties of+/- .05 grams.

ib physics shariq particle lab

Documents