Selamat Hari Raya 1429 Hijrah

Selamat Hari Raya kepada semua, maaf zahir d batin. jgn lupa study untuk exam.

wassalam.

Least Square Fit Calculation with Excel

Salam.

Today we’ll look at a technique of linear graph analysis called the least square fitting method. Why do we need to find a best fit line to a set of data in the first place? Because a graph is used to show whether there is a relation between the dependent variable (y-axis) and the independent variable (x-axis). In view of the lab practical that you carried out last week, we’ll plot the best fit line using the spreadsheed software Microsoft Office’s Excel. If you’re a fan of open source software, you could always use OpenOffice.org’s Calc (as useful as Excel, and it’s free).

Download the file  “Least squares fitting with Excel” (in pdf format) and open the file in your local computer.
least-squares-fitting-with-excel.

Having said that, if the example in the aforementioned file is too complicated (it is!!) then try this one.It’s more forgiving on your brain….save you guys the headache.. Click the following url linest.

Ok,this is your gift. song-for-you1

And then, there ’s chapter 30 on Communicating Information. Click on this: Radio

Welcome back. We’ll have to grind it out from now on!

Welcome back everyone. Hope you had a nice holiday, enough to replenish your depleted physical and mental strength. This week, we’ll be covering Section VII: Gathering and Communicating Information, which is divided into 3 topics: Direct Sensing; Remote Sensing; and Communicating Information. Notes and tutorials would be provided, for A1 group, things will be very hectic from now on, as you guys have less than 4 months before the big A2 exams. A2, by no means you guys/gals are off the hook…

Here’s some preview:

Direct Sensing : understand that an electronic sensor consists of a sensing device and a circuit that provides an output voltage. In between, the processing unit will process the input picked up by the sensor, and sends this processed signal to an output device. LDR is usually built from CdS (cadmium sulphate) sandwiched between two metal electrodes.  Then sketch the temperature characteristic of a negative temperature coefficient thermistor. Understand what does a transducer do and explain the way sound wave is transferred electrically via a microphone and speaker.

Do we use mass of H or mass of proton?

Somebody asked we several days ago regarding the use use mass defect formula. In Zm_H do we use the mass of hydrogen always, or use the unified mass of proton?
View this ppt presentation, regarding the issue.

mass of H or p+

Electron capture or positron emission?

Regarding to the latest test you guys took on Nuclear Physics, question 9 states that ⁶⁴Cu decays into ⁶⁴Ni isotope by means of positron emission (Schaum’s Outlines’ Applied Physics 4th Edition). But if you pay a visit to webelements at this hyperlink you’ll see that ⁶⁴Cu decays into ⁶⁴Ni by means of electron capture. Which one is correct? I don’t know for sure, butI know that whether by positron emission or electron capture, both type of decay would resulted in proton being converted to neutron.

Desktop Publishing (DTP) Tool

This is very simple to write: there are not many freeware and open source programs for DTP – let alone a portable one. So you can download this and use the program on the fly (after you’ve extracted it, of course). After you’ve done downloaded the file (PortableScribus.exe), just double-click it. Then, you’re ready to go!!!

(Errr…go where?)

RADIOACTIVITY

Yesterday we covered the last parts on nuclear reactions – namely fission and fusion process. Today we proceed with the last topic in this chapter: Radioactivity literally means the spontaneous emission of particles and/or energy from atomic nuclei. As a result, energy is lost/liberated.

Or, you may download it HERE. (click me!click me!click me!)
To Fara and Farhan, thanks for pointing out the mistakes in the notes.

Past Year Paper 1 June 2006

Let’s look at past year’s paper 1 june 2006.

Too small? Click here>> physics paper 1 2006.

This slideshow defines isotope and some of the elements with their isotopes.

Incidentally, we define the mass of all these periodic elements in terms of

unified atomic mass unit (u).

It is given that 1 u = 1.66 x 10 ^-27 kg.

Say that the atomic mass of silver (Ag) is 107.868 amu. This can also be expressed as

‘the relative atomic mass of silver is 107.868 g per mole”, or simply 107.868.

For your entertainment….

Nuclear Physics 2

We gonna have a slideshow today.
This slideshow describes the building block of our Universe.

It’s on the model used to describe atomic structure.

What is an isotope?

Atoms whose nuclei has the same number of protons but different numbers of neutrons. Isotopes are chemically identical (since their  electron numbers are identical) even though their nuclei have different masses.

27.Nuclear Physics

Chapter 27. Nuclear Physics

Content
27.1    The nucleus
27.2    Isotopes
27.3    Nuclear reactions
27.4    Mass excess and nuclear binding energy
27.5    Radioactive decay   [animation]

What is nucleus?

Our model of the atom changes as our experimental ability improves. Today’s atomic theory tries to explain the observations made with accelerators. The current “quark model” of the atom is a hypothesis based on current atomic theory. Now the physicists discovered, so far, that atoms are made up of 12 matter and antimatter particles.

Six types of fundamental matter particles are classified as leptons. Three kinds (called flavors) of these, the electron, the muon and the tau, exhibit a property called electrical charge (which can be negative, positive or zero) in the amount of -1. The other three flavors are neutrinos, which carry zero electrical charge. There is one type of neutrino corresponding to each type of charged lepton. These three neutrinos are referred to as the electron neutrino, the muon neutrino and the tau neutrino. As fundamental particles, leptons are assumed to be indivisible, and there is no evidence that they have any size.

There is a type of antilepton for each of these six kinds of lepton. The antilepton corresponding to the electron is called a positron; the other antileptons are the antimuon, antitau, anti-electron-neutrino, anti-muon-neutrino and the anti-tau-neutrino.

The six leptons (and their corresponding antileptons) are cross-classified into three lepton generations, each one generally lighter than the next: the electron neutrino and the electron (first lepton generation), the muon neutrino and the muon (second lepton generation) and the tau neutrino and the tau (third lepton generation).

And that’s just the start, my dear students…. Historically people during the ancient civilization had tried to explain the creation of the Universe. Here are some of them who helped us understand better our Universe.

Democritus  (Greek philosopher around the year 400 BC.)

Democritus concluded that matter could not be divided into smaller and smaller pieces forever. Eventually, the smallest piece of matter would be found. He used the word atomos to describe the smallest possible piece of matter.

John Dalton (English chemist that proposed first atomic theory in 1803. )Points of Dalton’s Theory:

1. All elements are composed of indivisible particles.
2.Atoms of the same element are exactly alike.
3.Atoms of different elements are different.
4.Compounds are formed by joining atoms of two or more elements.

J. J. Thomson  (English scientist who discovered electrons in 1897. )

Sometimes called the “plum pudding” model, Thomson thought of an atom as being composed of a positively charged material with the negatively charged electrons scattered through it.

Ernest Rutherford  British physicist who discovered the nucleus in 1908 (His idea, but the experiment was carried out by Geiger and Marsden, his research assistants).
Rutherford’s model proposed that an atom is mostly empty space. There is a small, positive nucleus with the negative electrons scattered around the outside edge. He found that the atom consists of nucleus (proton and neutron as its constituents) where mass is concentrated and nucleus is orbited by electrons. (We use the term ‘orbit’ loosely here).

Niels Bohr  Danish scientist who proposed the Planetary Model in 1913.
Electrons move in definite orbits around the nucleus, like planets moving around the Sun. Bohr proposed that each electron moves in a specific energy level.

 Sir James Chadwick  discovered the neutron in 1935.  His wave model, based on wave mechanics, proposes that electrons have NO definite path in an atom. The probable location of an electron is based on how much energy it has. The more energy an electron has, the farther from the nucleus. The small, positively charged nucleus is surrounded by a large space in which there are enough electrons to make the atom neutral.