Measuring coins >

DENSITIES OF THE PHILIPPINE COINS

We use coins everyday. Many changes have been present in our national coins we use right now.

As a result, this has led to the different properties these coins have. After we measured the rice grains, which is a tedious task, we now moved on to measuring coins. Using calipers again, we sort of got a grip on how we should measure the coins. Measuring them were way, way easier than the rice grains. 

Anyway, as I've mentioned a while ago, our own coins have different properties, look: 

  Fig.1. Different Philippine coins. (source: images.delcampe.net)

It seems that as the value of the coin increases, it's diameter also increases. Of course, as we measure the properties we need to quantify, errors are present. That is, the "measurement" we will gather should always depend on the limitations of the devices we use for measuring plus our judgement on the reading. We (our group) were only able to measure 4 of the coins shown above (fig.1.), namely the:

 where:
          d = diameter                                   t = thickness
          d(in) = diameter of the inside        m = mass
                        

• 5-centavo coin: d=15.1 mm, d(in)  = 3.16 mm, t = 1.1 mm, m= 1.9g
• 25-centavo coin: d= 20 mm,  t = 1.6 mm, m= 3.8g
• 1-peso coin: d= 24 mm, t = 1.168 mm, m= 5.4g
• 5-peso coin: d= 27.16 mm,  t = 1.18 mm, m= 7.9g

Error propagation means that when one doesn't take account the uncertainty involved before using mathematical operations between his/her measured values (which are inherently uncertain),  the error will propagate. Basically, the computed value would have discrepancies from the expected value of measurement. It would probably be "away" by a matter of decimal places. Small, but the errors using operations might be big to be noticeable. To avoid these, one must continue the mathematical operations he/she started until he/she will reach the point where it is the final answer to all operations involved, rounding off with respect to the significant figures rule.

Only Authorized Personnel Are Allowed To Enter

THE RESEARCH WING

When you enter the NIP building at its main entrance and reached the lobby, a glassy building would probably be the first thing you'd see. That is the Research wing of the NIP. Many months ago, just before the first semester officially starts we entered the R-wing, we only got to see the "center" of it, took a picture around the big NIP logo on the floor then done.

Weeks ago, we visited it again. Our guides said that there are currently 6 laboratories here in the NIP:

1. Condensed Matter Physics Lab
2. Instrumentation Physics Lab
3. Structure and Dynamics Lab
4. Photonics Research Lab
5. Theoretical Physics Lab
6. Plasma Physics Lab

As we entered each of the labs, I realized that Physics is amazing. No kidding, it's amazing to be a physicist someday. I think I should say my brief insights upon entering. While inside the Condensed Matter Lab, especially the supercon, they showed us a video about a superconductor that levitates or suspends in midair when cooled to a certain temperature. Too bad, it's just a video, not the real thing. :(

The Instrumentation Lab (popularly known as "Instru") deals with the application of Physics in a more realistic way, such as their research on the telecom companies, gas companies, number of characters involved in a tweet, etc. They also have a group called "VISSER" which invents materials (e.g. motion detector / sensors) for high school students. I think that's remarkable because they help students appreciate science! "Instru" has the most groups or clusters among all the labs.

Upon entering Structure and Dynamics Group (SAND) Lab, it looks like a computer shop with a big whiteboard full of equations. (sorry for my first impression :D ). Little did I know, SAND specializes in computer simulations of different kinds of systems. Ah kaya pala..

On our lab tour as a class, we didn't get to see the best of Photonics lab. But they have cool lasers and machines there. But when we were the ones guiding high school students in the Photonics (in short we had the chance to see the lab again) we saw hologram of a girl. Ah, cool. :D

There is one thing that sets Theoretical Physics lab apart from other labs: THERE ARE NO "FANCY" MACHINES. But they have books, equations, books again, and a coffee maker. Yes and  they're proud of it. Also, I wonder why they have a salad book there. 

Finally, the Plasma lab. This lab studies about plasma, of course.The "thing" I remembered about this lab is the plasma pen. It looks like a rocket boost but it's safe for someone to touch it. 

These are just few of the things we did during the lab tour. My favorite labs (I'm thinking of entering one of these if there's a chance) were the Photonics lab and the IPL specifically VISSER. Pero ang Theory ang pinakamabango, amoy kape. In conclusion, all of the labs were really fascinating in their own way. 

And that's what makes NIP the Philippines' best physics institute.  

Kulang nalang ang golden ticket, RFID.

MY FIRST-EVER [and official] PHYSICS LAB CLASS!

Meanwhile in F106...

As the title says, this is my first-ever laboratory class that will show how experimental Physics actually is. Having my excitement on that day, I will share a short narrative on what happened on the first day...

It was Monday morning (of course, Monday blues included...) and while I'm on my way to NIP, the first thought that came to my mind was: "Yes, first day sa physics lab!". Also, CRS already posted who will be our professor in the lab. I saw that it is Sir Batac (Hi Sir! :D). I think many of my classmates already know him because he was our Physics 10 professor last semester. So my first-day jitters about our teacher didn't prolong. He introduced himself to the class and after that he asked us to introduced ourselves as well by following this format (as far as I remember):

•  Name:
• Course:
• High school attended: 

 and *drum roll*...

• WHY DID YOU CHOOSE PHYSICS / APPLIED PHYSICS?:

Well, the last question. I listened to each one of my classmates and we actually had different answers. Most of them love Physics ever since high school (I'm not one of them though..) :))

OKAY......

The orientation, just like every first meeting of every subject, basically involves stating the syllabus, the rules we should follow in class, grading system, and other formal stuff. But when we discussed what our coverage in experiments will be, another block of excitement piled up on a previous excited block. Especially we were surrounded by many measuring devices or instruments in the room. I hope we would try them all some day. :)

WARNING: MEASUREMENTS ARE UNCERTAIN.

IS MEASUREMENT RELATIVE?

We're humans, the contemplators of the universe. That's it. We love, or should I say it is natural for us to invent things that were not here, not within reach to make our lives easier. Let me cite an example, alphabets. Language is an indispensable part of our existence. Can you imagine a language which didn't need the help of a symbol for giving meaning to every single word in it? It's difficult to think one, right? Another thing we wonderfully "made-up" although many of us hate this.. mathematics. We cannot deny that we were enlightened on how the universe rationally moves or goes on by using this wonderful invention. We're in great need of understanding the whole truth of our dear universe. I guess that was delivered too sentimental. In addition to that, since I'm taking up Physics, it's important to quantify things that are measurable, if it's not measurable, it's not-so-physics. Anyway, why am I saying these things? How do these answer the BIG question above? On my last post, I mentioned that measurements are products of arbitration. Which means that.. [look at the title of this new blog -- the one with the "warning"].

activity 1
 Last time, I said the three major factors that affect your measurement according on what I've learned during our discussion or basically what I wrote on my notes:

1.  The nature of the quantity being measured (e.g. a person is measuring a roughly surfaced object using a ruler *goodluck*)
2. Judgement of the experimenter (e.g.  the measured data lies between 1 m and 2 m and the experimenter decided to report the data as 1.500 m)
3. Limitations of the device (e.g. some graduated cylinders have more detailed calibrations than others)

  With these factors in mind, I realized the point I brought up, that measurements are the results of arbitration. Yes, they're just made up. However, these data gathered are very important for the technical people.

 

activity 2

  

  I already made a short narrative on how we measured every, single rice grain by using a Vernier caliper and it mainly focuses about patience, data, patience, stuck fingers, patience, oh well. The real challenge was measuring the grains using this thing: 

                                                   (image from headway-tech.com) 

A micrometer caliper. Luckily, last meeting, we had the chance to use this as a measuring tool. Although, this looks harder to use than the Vernier caliper, we (our group) ironically measured more grains using this kind. I bet we learned to be more focus this time. Anyway, like our first measurements using the Vernier, the data we collected using the micrometer corresponds to what we expected. I think 90% of the grains measured as 7.00+ mm. The other 10% are mostly dominated by the 6.00+ mm, otherwise it's in the 8.00+ mm line.

Last of the three factors that affect the measurement of an object tells us that no measuring device can be so accurate. Hence, those two kinds of calipers we used, also have their own margin of error. The Vernier caliper has an error of ± 0.02 mm, while the micrometer has ± 0.01 mm. It means that micrometer is more accurate compared to  the Vernier by 0.01mm, which is kinda big difference. 

I think the average length of the rice grain is the data of an international research which says that length of the rice grain is 7.09± 0.36 mm. This, I believe, is true because they have measured a lot of rice grain. Our professor said that they were able to measure a thousand rice grain.A matter of 950 grain-difference to our data. So obviously, they got a wider gathering of data, and a more acceptable mean. I think the next question may be: What is the variant of rice they measured?

Activity 1: On Measurement

Last Monday, we discussed about measurements. I think every laboratory class has to allot time for simple discussion regarding measurement. Especially, this is a Physics lab course, so measurement is a part and parcel of every topic. Well, I've learned new things and few techniques which is actually handy for laboratory class. I guess I'll mention my favorites of those. First is that measurement units are products of arbitration, that no measurement is literally exact. It kinda struck me, though. Second, is that all the measurements are based on the judgement of the person, like if you see a reading between 1 and 2 mm., most people  would probably bet that reading is exactly 1.5 mm regardless of many considerable yet small decimal values. And last, the limitations of the device you're using affect your measurement.

Activity 2: Using Calipers

So this is the activity that we will finally apply and get to see what the results would be like... We're going to measure the length of a rice grain. Sounds simple. But personally it's a no. Honestly because, back when I was in high school, I've never touched or seen this:

A Vernier caliper. (image from amazonsupply.com)

and even this:

                                                 A micrometer caliper.  (image from amazonsupply.com)

 So apparently, that was my first time to use laboratory apparatus like these. Although, we did not have enough time to the micrometer for this meeting..  Okay I'm going to tell how our group measured the rice grain. At first, we were warned by our instructor using the Vernier caliper. He said that you must check the measurement readings by holding the caliper upright because a little parallax could cause you a big trouble while measuring. I tried it myself, reading the measurement slightly slanted and it is true! 

Then, we measured the rice grain one by one, piece by piece. It's kind of hard because whenever it's my turn to measure the grain, my thumb and index finger got stuck as well. We set our goal to 50 grains but then our group ended up measuring only 43 grains. One thing I noticed from our results is that all our measurements (in mm.) are relatively close to each other. If I remembered our data right, we only had 2 out of 43 readings containing 6.00+ mm. The rest mostly measured as 7.00 + mm. .Our instructor also shared the results from a research about the average length of rice grain from a high-resolution experiment. He said that those researchers were able to measure at least a thousand grains of rice. Woah, they were so patient!

Overall the two activities, I think, train us to be careful or meticulous about the objects we want to measure.... and be patient, of course. It's hard to measure a grain of rice, especially if you're trying to measure a thousand of them!