What is Mole?

• Mole is the unit of the Amount of Substance of any matter
• It is written as "mol" for short.
• Same number of moles of different substances contain same number of particles.
• Same number of moles of different substances possess different mass.
• The amount of particles present in 1 mole of any substance is 6.02x10 (which is also known as Avogadro's Number)

What is Avogadro's number

The fixed value of the amount of particles, atoms or molecules present in One Mole of any substance which was calculated by Amedeo Avogadro, an Italian Scientist who is most noted his contribution to the molecular physics and He was also the Count of Quaregna and Cerreto.

Avogadro's Number:

• The amount of atoms, molecules or particles present One Mole of any substance is called Avogadro's Number.
• The value of Avogadro's Number is: 6.02x10²³
• Avogadro's Number is denoted by or The symbol of Avogadro's Number is: N_A

Law of Conservation of Momentum

Q. Explain the Law of Conservation of Momentum with the help of an example:-

Introduction:

One of the most powerful laws used in Physics is the Law of Conservation of Momentum which is given by Sir Isaac Newton, which states that:

Statement:

The total momentum of an isolated system before collision is always equal to the total momentum after collision.

Define Momentum

Q. What is Momentum?

Definition:

The quantity of motion present in a body is called its Momentum. The amount of momentum in a body can be measured by the product of its mass and velocity.

Explanation:

Every moving object has some amount of motion and that amount of motion is known as momentum, for example if a boy is running with some velocity and certainly it has some mass as well. If we take product of his velocity with his mass or if we multiply its mass and velocity then the result obtained will be its momentum.

Formula:

Momentum = mass × velocity
P = m × v

Unit of Momentum:

kg m/s2

Newton's Law of Universal Gravitation

Q. State and explain Newton's Law of Universal Gravitation:-

Introduction:

In 1687, Sir Isaac Newton stated the Law of Universal Gravitation between two bodies.

Statement:

It states that, Any two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of distance between them.

Application to the Principle to arrange an Extra Class:-

To,

The Principle,
Name of School/Institution,
Addres,
Date: xx.xx.xxxx

Respected Sir,

With all due respect, I state that I am the student of class X. I am monitor of the class. Our annual examinations are near and our class is very weak in English and Maths that is also evident by the half yearly examination. Our English teacher was regularly on leave because of his ill health and the Math teacher was very busy in his thesis.

Therefore, I request you on behalf of my whole class to arrange an extra class for these subjects as soon as possible. We will be very thankful to you for this act of kindness.

Yours obediently,
XYZ

Paragraph on: The School Peon

The person who sits outside the Principle's office or outside the school gate is the school peon. People think that a peon is not a important person but the Principle very well knows how important his services are for the school. We don't know how uppercase his services are for the school.

A Paragraph on Picnic

Everyone needs a break from the hardships of life and picnic is the best idea for that. Last month, me and my friends decided to go on a picnic at Swat. Our examinations were over we were all exhausted, so we though picnic was the best thing to refresh our minds.

Conditions of Equilibrium

Q. What are the conditions of Equilibrium?

There are two conditions for a body to remain in the state of Equilibrium.

First Condition of Equilibrium:

States of Equilibrium

Q. State and Explain States/Types of Equilibrium :-

Ans:
There are three states/types of equilibrium.

1. Stable Equilibrium
2. Unstable Equilibrium
3. Neutral Equilibrium

Importance of Physics in Our Daily Life

Q. Describe the importance of Physics in our daily life:-

Physics plays an important role in our daily life and is the key to solve our future problems. Physics has made our life easier and more efficient. For example, when we wake up early in the morning while azaan being called from a mosque on a loud speaker or when we wake up by an alarm clock that alarm clock and loud speaker are inventions of physics. When open water tap for ablusion to offer prayer or simply to wash ourselves the water reaches us following the laws and principles of physics. All means of transports such as bicycles, cars, buses, trains and aeroplanes are all working on the principles of physics.

Physics and its Branches

Q. What is Physics?

Definition:

Physics is a branch of Physical Science that deals with the study of matter, energy and the mutual relationship between them.

Explanation:

Short Note: An African Village

Africa is the second largest continent in the world, consisting of more than thirty seven countries and Nigeria is the biggest country of west Africa. The people of Nigeria are mostly farmers. They live in huts under large Bush Areas. There are no roads or streets in Nigerian villages and the huts are scattered in bush areas.

Letter to Younger Brother advising him to take part in games:-

Examination Hall

Address
Date: xx.xx.xxxx

Dear brother,
Greetings!

I am fine with the grace of Almighty Allah and I hope you are doing good as well. It is always advisable to make the best use of student life, as this part of life makes the character of our personality. However, this does not mean that you study day and night and forget about your health. I have been told that you do not play games as you are shy of doing so. I therefore advice you to take active part in games because games are also a necessary part of life. Games help us to stay fit and shape our body. You should try to overcome your shyness and participate in sports and games. As an elder brother I advice you to take part in games as games make us healthy, wealthy and wise as the adage goes health is wealth.

There fore, always try to take active part in sports and divide your time in study and games. I am sure you will act up on my advice.

Your affectionately
XYZ

Short Paragraph on Quaid-e-Azam Muhammad Ali Jinnah:-

Quiad-e-Azam Muhammad Ali Jinnah was the founder of our beloved country Pakistan. He was born on 25th December, 1876 in Karachi. His father name was Jinnah Poonja. He received his early education from Karachi then he went to England and took his Barrister's degree from Linchon's Inn.

Write a Short Paragraph on Railway Journey:-

During the last vacations, my favorite teacher Sir Ghulam Asghar Bhutto asked to take me and my friends to Lahore and spend a few days there. We were asked to arrive at the station at seven o'clock

On the next morning we arrived at Hyderabad station at about seven o'clock and boarded the Lahore Express at about eight o'clock and the train left in time. We found that the compartment was full of passengers and piles of luggage. Somehow I managed to sit by the side of a window.