Thursday 26 April 2018

Ramadan And Studies - IOU Blog



Ramadan and Studies: 10 Tips for Hardworking Students 

Dear people,
You might want to read this article from Islamic Online University Blog as Ramadan is just around the corner and so are the O Levels and this might be helpful.  🕘 💪🅪📋📘📏📐🍏🌗

Saturday 10 March 2018

O LEVEL PHYSICS - KINEMATICS

Kinematics is a branch of Mechanics that is concerned with pure motion and is not concerned with the forces involving those motion. 

Distance (in terms of kinematics) is length covered by a moving object.
Displacement is the linear distance between two points.
Displacement is the linear distance traveled by an object from the starting point to the endpoint.
Linear distance means distance in a straight line.
The  SI units of both Distance and Displacement is in meters(m).
Distance is a scalar quantity.
Displacement is a vector quantity.

Let's look at this concept with an example.

Example 1:
Suppose a car travels from A to B and then from B to C (see diagram). What is the car's total distance and displacement?  

Answer: The car's total distance is the length that it moved. That is,
distance = 15 + 7 = 22m

And it's displacement is

displacement = 10m

Because this is the linear distance covered between the starting and the endpoint.



The car now further travels from C to A. What is now the car's total distance and displacement starting from A and traveling back to A?

Answer: Now the total distance will be,
distance = 22 + 20 = 40m

And the total displacement will be
displacement = 0m

Because the starting and endpoints are the same and there is zero meters of linear distance in between them.  






Now moving on to speed and velocity.

Speed is rate of change of distance. It is measured in meters per second (m/s). It is a scalar quantity.

speed = distance traveled / time taken

Velocity is the rate of change of displacement. It is also measured in meters per second (m/s). It is a vector quantity.

velocity = displacement / time taken  




You would find plenty of examples on speed/velocity calculations on your book. Therefore I am not adding another one here. Next we are going to look at Acceleration.

In the simplest of terms...


Acceleration is the rate of change of velocity. It is measured in meters per second square (m/s^2). 
It is vector quantity.   

acceleration = change in velocity / time taken
 
But the question still remains of what acceleration actually is or what is happens during acceleration.
So if we now look at a deeper definition...

Whenever there is a change in velocity, there is an acceleration. If the velocity is not changing then there is zero or no acceleration. But another thing to note is that velocity is a vector quantity so if the direction of an object changes, then it's velocity changes. Hence it's acceleration changes.
So, either change in magnitude or change in direction, both results in an acceleration. (This is an important point to note as this often comes as a conceptual question in CIE O Level Exams). 

There are two types of acceleration:
  •  uniform acceleration
  •  non-uniform acceleration  

Uniform acceleration
Uniform acceleration is when the rate of change of velocity remains constant.
Another name for uniform acceleration is constant acceleration. Constant acceleration means that the acceleration does not change but remains constant. It does not increase or decrease with time. 

Tuesday 25 July 2017

Number - Mathematics D


Number
Cambridge O Level Mathematics D (4024)


This chapter would be quite long and might get boring at times as you might know most of these things. I would rather suggest you to go thoroughly through the number system and give the rest of  the chapter a quick read and update your what you've learned if you find anything unfamiliar.





Number systems:

Definitions of different types of numbers we use:
  • Natural numbers: Natural numbers are counting numbers. Natural number include whole numbers only, however, it may or may not include 0 (zero). Natural numbers only include positive numbers.  E.g. {1, 2, 3, 4, 5,...}.
  • Whole numbers: All non-fractional numbers are called whole numbers. It includes zero. E.g. { 0, 1, 2, 3, 4,...}. Any number like 0, 7, 212, 1023 are all whole numbers.
  • Integers: Integers include all negative and positive non-fractional numbers (or whole numbers) and 0 (zero). E.g. {...-3, -2, -1, 0, 1, 2, 3,...}
  • Rational numbers: Rational numbers are all numbers that can be expressed as a ratio or a fraction. This would be possible if both the numerator and denominator are whole numbers or more specifically integers. E.g. { 9.0, 8/1, 2/3, 0.55555} are examples of rational numbers. NOTE: If you put 2/3 in a calculator, you would get the number 0.66666666 and it would go on forever. These are also rational numbers and are expressed using a recurring decimal. A recurring decimal is a decimal number that has digits that repeat forever. 
  • Irrational numbers: An irrational number is a number that cannot be expressed as a fraction. This is because in these numbers, there is not a finite number of numbers when written as a decimal. Instead, the numbers go on forever without repeating. Hence, these numbers can't either be expressed using a recurring decimal. E.g. { √2 = (1.41421356…), π = (3.14159265…)}
  • Real numbers: A real number is any quantity on the number line. It includes all of the types of numbers mentioned above. E.g. {0, 1, 2, 2.5, 2/3, √2, π}. (√(−6), negative root of something is NOT a real number).
  • Imaginary number: An imaginary number is a number which is not a real number. E.g. Negative root of something (√(−6)).
For the symbols of these numbers, refer to your math D syllabus, page#22.



Thursday 18 May 2017

Straight line graphs - Additional Mathematics

Straight line graphs
Cambridge O Level Additional Mathematics 4037

You must know the chapters co-ordinate geometry and logarithm before starting this chapter.

Equation of straight line graphs:
The equation of a straight line is

 y = mx + c

where, m is the gradient;
c is the y - intercept.

The formula of gradient, m = (y2 - y1)/(x2 - x1)




In these sums, you are given an equation which you have to transform into a straight line equation. The type of equations that you get are: y = ax^n and y = Ab^x .