Blog

Why the water is blue?

Have you ever asked yourself a question – why the water is blue? Obviously,we mean something large like sea or the ocean. If you take a glass of water, the liquid seems transparent and colorless, yet vast amounts of water possess certain colors. Let’s try to understand why it happens.

The color of the ocean is defined by the mechanism of absorption and dissipation of light by water molecules. Geoscientist Vasily V. Shuleikin described this complicated mechanism only in 1923. It turned out that water molecules move oscillatory, thus, they absorb waves of different length. Red wavelengths are predominantly absorbed, blue are less. Water molecules scatter blue wavelengths by absorbing the light waves and reemit those waves in different directions into the air, while red wavelengths are “swallowed” by the ocean. This makes ocean seem blue, and this is exactly why underwater photos are so full of blueness. (more…)

Assignment help on Master’s and Ph.D. level

We continue to study and analyze effiсiency and reliability of our helping service. It turns out that we increasingly often help students, teachers, researchers in carrying out their research papers and assignments.

You probably know that assignments leveled as Masters and Ph.D. are very complicated, and that’s so to a great extent because they are usually highly specialized. It is very important that among our staff there are specialists who can help to carry out such kind of tasks. Normally, we are asked by our customers to fulfill certain part of the paper – to describe a mathematical model or to write a program performing the calculations, to build a probabilistic or statistical model of the process under investigation. (more…)

How to calculate 4X4 determinant? Do math with our expert

We’re continuing to prepare math tutorials. Hopefully, it will be helpful for you and you won’t be in need asking our experts something like “Do my math homework for me, please! I’m stuck..” This is the second part of our tutorial explaining how to calculate determinants. We’re asked to calculate the determinant of the following 4×4 matrix:

$A=\begin{pmatrix}-1 & {1} & 4 & 2 \\2 & -1 & 2 & 5 \\1 &2 & 3& 4\\3& 4& -1 & 2\end{pmatrix}$

Recall that only square matrices have a determinant, for non-square ones it’s not defined. Matrix $A$ is a square 4×4 matrix so it has determinant. Here we have no zero entries, so, actually, it doesn’t matter what row or column to pick to perform so called Laplace expansion. Let it be the first column. It means that we set $j=1$ in general formula for calculating determinants which works for determinants of any size (more…)

Why carbon is contained in steel?

Steel may well turn to be applied more widely than any other material, present in lots of familiar items starting from your fridge and cell-phone and ending up with details of ocean liners, planes and space craft. You probably know that by steel we mean an alloy mainly composed of iron and carbon. Due to the presence of the latter, in contrast to pure iron, steel acquires higher strength characteristics. Have you ever wonder why carbon is contained in steel and, besides, how it alters properties of iron so substantially? Actually, this was the question of our visitor, it sounded as “why steel has carbon in its structure? is there any simple explanation?” We provided the short answer and, as the topic is unquestionably interesting, decided to consider it in detail in our blog.

Humans started to use iron a long time ago. The oldest item made of meteoric iron was found on the territories of modern Iran, Iraq and Egypt, and is referred to the period XI-IV BC. Approximately starting from the first millennium BC usage of iron is wide-spreading continuously. Primarily because of the transition from bronze to iron civilization growth got more intensive. (more…)

Website that does your homework wherever you are

Surfing the Internet to find a website that does homework for you? Great news, you’re at the right place!

We do our best to help you doing your assignments as good as possible. We’re fully aware that homework quality is very important and delicate matter and that’s why we’re aiming at constant improvement of our homework making service. We understand that when our clients are in need of help it’s our duty to minimize risks and provide excellent results within your deadlines. We have analyzed our work and got unbelievable results. It appeared that we have already helped a great number of people from 120 countries. (more…)

Gaussian elimination method – case of inconsistent system

We’re continuing to consider Gaussian elimination method. Earlier we’ve prepared several tutorials covering theoretical background and examples including application of matrix representation. Yet, all those examples suggested systems of linear equations which have a solution. That’s not always so, though. In your homework or linear algebra assignment you can face different situations. In fact, there are three possibilities: system of linear equations can have either unique solution, or infinitely many solutions, or no solution at all. We’ll discuss the last case in this section.

Let’s solve the following system of linear algebraic equations:

$\left\{ \begin{aligned}2x_1-x_2+3x_3=4\\-3x_1+2x_2+x_3=5\\-4x_1+2x_2-6x_3=1 \end{aligned}\right.$ (more…)

Why large animals (elephants, rhinos, crocodiles) are slow?

Big animals existing nowadays have a lot in common. Among other similarities, all of them tend to move slowly. You probably know that large animals like elephants, rhinos, etc. move slower than smaller ones like mice, for example. Of course, you might object that named species can move with considerable speeds and, say, elephant outruns human with no effort at all. That is so, but in average they do move pretty slow. In this section we’re going to discuss the reasons why it happens. (more…)