Embedded Files
by Year 9 students
This page contains Physics contents discussed in class and re-written by students in prose form to show how well they understood the materials with some elements of creativity and link to the holistic being that the school is promoting through the P.I.A.G.E.T. values. Classmates read the contributions when doing home revisions and/or serve as peer support to others may have fall short of the standard, failed to earned the content-based badges.
Contributions in this page are also part of the 5% PROJECT component of the Final Grade in each term of the school year.
Apps as an Alternative for V.C. and Micrometer in time of School Closure
Reviewed by Jin Hyo, 27 July 2020
Vernier Caliper is an app, by Fometescu Octavian, that helps us to practice measuring length with Vernier calipers and micrometers. According to this application, it is an educational application that wants to support people who want to study by themselves to use various measurements.
When you open the application there will be choices like Vernier caliper, micrometer, and other measuring tools. When you select Vernier caliper, there will be a model of vernier caliper showing its main scale, Vernier scale, inside jaws, and outside jaws. An object placed between the jaws are simulated as if you are doing it in real life. By moving the vernier scale into the right side, we can measure the objects’ length by reading the main scale and vernier scale and then adding these measurements up.
For the micrometer, the parts like main scale, thimble scale, anvil, spindle, and knob are shown and can be manipulated as if you are using it in the lab. Object, in the app also, is to be placed between anvil and spindle. By rotating the knob upward until it clicks. At this point, you can measure the objects’ length by reading the main scale and thimble scale and then add.
Nowadays, due to coronavirus, every student is doing distance learning at home. For those people who can't go to the lab these days for experiments to measure objects with vernier calipers or micrometers, this app is very much helpful. Even when the normal school restarts, this app can still be used when students want to practice and get familiar to how it used and hence, develop better practical skills. This ‘Vernier Caliper’ application can provide help to students anywhere they are as long as they have their phones with them.
Dealing with Significant Figures
Summarized by Stanley, 26 July 2020
All these came along with the fact that there are no exact measurement in the Sciences, particularly in Physics. Every figure or data from our experiments in the lab came from specific measuring tools, which only provides estimates of physical quantities because of the tools' limitations. This is why our answers should always be expressed in proper number of significant figures and be observant with the number of decimal places.
The mentioned tools, or better say, all tools in the laboratory are graduated over and over again to increase precision, or closeness to the actual value of the quantity. However, there will come a point that graduation or smaller divisions are not possible anymore. Hence, precision always stop at some degree, that is to say, tools can be modified to get closer and closer to a certain value but never can it measure an exact value. Because of this, operating with these measurements require new rules.
The calculator, whenever it operates on numbers, considers all you typed-in as exact values. Since our data or values in Physics are estimates, taking all what are displayed ion calculator is sometimes a mistake. What we should do is not to write all the figures that are displayed on the screen of the calculator. We must use the number of significant figures of the number that you are calculating for the answer or align the final answer to the measurements' number of decimal places. Taking all digits shown on calculator may be too less precise or too precise. Calculator is not a God that we should not take all but only those digits it shows that could make our final result appear practical or logical. (See Attachment 1S and Attachment 2S above for examples.)
This rule is applicable to all subjects or anything that deals with estimated values, not just in Physics. Your Math subject deals with mostly numbers assumed to be exact, and so your teacher may require you to express exact answers, too, or instruct you to express it in some number of decimal places.
How to Read Vernier Caliper and Micrometer
Tips from Edward, 27 July 2020
Ahh these pieces of magical equipment that the ruler would always have dreamt of having that additional decimal points. Unfortunately for the ruler, her older cousins are used to deal with closer measurements to actual length that just require those fine precisions.
At first glance, these equipment looks like they need top tier certified scientists to be able to use them properly without worrying of breaking anything. However these equipments are simple to understand and use. Once you get used to it you’ll be saying goodbye to that ancient ruler of yours.
There are 7 main components to a vernier scale, all of which are shown in the Fig. 1E below.
Fig. 1E
Fig. 2E
Once you have squeezed in the item you would like to measure using either the inner, outer jaw or the depth rod. The first step would be to read the Main scale. The first 2 digits would come from the 0 line of the vernier scale pointing towards the main scale, take the reading of the digit to the left. For example, the measurement lies in between 5.5cm and 5.6. The smaller reading should be taken. The third and last digit would be the line from the main scale which makes a perfect straight line to that of a number on the vernier scale. The straightest line should be the reading.
Take Fig. 2E as an example. The 0 on the vernier scale points out towards the numbers 2.5 and 2.6. Here, 2.5cm should be taken. The straightest line from the vernier scale and the main scale on this particular example points out towards the number 8. So hence, the final answer would be 2.5cm + 0.08cm = 2.58
Fig. 3E
Reading a micrometer (see Fig. 3E) is slightly more complex, but it isn't something impossible to read. What makes a micrometer special compared to the vernier and ruler is that this equipment could measure up to 3 decimal places in centimeter form. First Step on using the micrometer is placing something between the spindle and anvil, make sure there is a clicking sound before tightening the lock. The scale on the micrometer is in the form of Millimeters. Step one on reading the micrometer is looking at the last line (which represents a number) on the sleeve scale which isn't covered by the thimble. In the figure above, the last line to be seen is the 9th line. So this will be imputed in the form of 9mm. Afterwards Read the line and number on the thimble that is straightest with the index line. If the index line crosses between two numbers on the thimble, the lower value number should be taken. In the case above, the index line makes a perfect straight line with 05 on the thimble scale. Therefore this would be read as 0.05mm. Adding everything up would give 9 + 0.05 = 9.05 mm or also 0.905cm.
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