#### Buoyancy and Archimedes' Principle

November 28, 2020

A mug filled with water appears to be heavier when it is lifted from bottom of the bucket to above the surface of water than the mug within the water in the bucket.

#### Mass and Weight

November 24, 2020

Mass of a body is the quantity of matter contained in the body. Mass of an object is constant and does not change from place to place. It remains the same whether the object is on earth, on moon or anywhere in outer space.

#### Motion of an Object Under Gravity

November 20, 2020

The g is constant near the surface of earth. Therefore, all the equations for uniformly accelerated motion of bodies become valid when acceleration a is replaced by g.

#### Acceleration Due to Gravity

November 16, 2020

The speed of a falling stone increases continuously. The stone is accelerated due to force of attraction between the stone and the earth. This acceleration is called the acceleration due to gravity.

#### Newton's Law of Gravitation

November 12, 2020

Newton expressed the law of gravitation in the language of mathematics.

#### Force of Gravitation

November 08, 2020

A force is required to change the state of rest or of motion of a body. All objects when dropped from a height fall towards the earth. Why do objects fall towards the earth?

#### Thrust and Pressure

November 04, 2020

Some bodies like table, desk, bucket full of water press the floor with a force equal to their own weight. The weight is the force acting vertically downwards. As the surface of the floor can be taken as horizontal, therefore, the force with which each body presses the floor is directed perpendicular to the surface of the floor.

#### Force of Friction

November 01, 2020

A ball rolling along the ground stops after moving through some distance. Similarly, a moving car begins to slow down the instant its engine is switched off and finally it stops.

#### Conservation of Momentum

October 29, 2020

Law of conservation of momentum is a very important law of science. According to this law, if two or more objects collide with each other, their total momentum remains conserved before and after the collision provided there is no external force acting on them.

#### Newton's Third Law of Motion

October 26, 2020

Newton in his third law of motion stated a relation between action and reaction. According to this law, to every action there is an equal and opposite reaction.

#### Newton’s Second Law of Motion

October 23, 2020

According to Newton’s first law of motion the application of an unbalanced force brings a change in the velocity of an object. Thus, the force can produce a change of momentum. Newton’s second law of motion establishes a relationship between force and change in momentum.

#### Momentum

October 20, 2020

The force required to stop a moving body depends upon its mass. Suppose two balls of same mass are moving with different velocities. Which ball will need more force to stop? The faster moving ball require more force to stop it. Thus, the force required to stop a body also depends upon its velocity.

#### Newton's First Law of Motion

October 17, 2020

An object offer resistance to change in its state of motion. This was studied by Newton in detail and he presented his findings in the form of three fundamental laws that govern the motion of objects.

#### Inertia

October 14, 2020

The inertia is the tendency of objects to stay at rest or to keep moving with the same velocity.

#### Meaning of Force

October 11, 2020

If you place a ball on a flat surface, it will remain there until unless you disturb it. It will move only when either you push it or pull it. This push or pull acting on an object is known as a force.

#### Uniform Circular Motion

October 08, 2020

Consider the motion of an object along a circular track of radius R through four points A, B, C and D on the track. If object completes each round of motion in same time, then it covers equal distance in equal interval of time and its motion will be uniform motion.

#### Equations of Motion

October 05, 2020

Consider an object moving with uniform acceleration, a. Let u be the initial velocity (at time t = 0), v, velocity after time t and S, displacement during this time interval. There are certain relationships between these quantities.

#### Acceleration

October 02, 2020

In the non-uniform motion, the change in velocity in different intervals of motion is different. This change in velocity with time is called acceleration.

#### Velocity-Time Graph

September 30, 2020

Take time on the horizontal axis and velocity on the vertical axis on a graph paper. Let one division on horizontal axis represent 1 s and one division on vertical axis represent 10 ms–1.

#### Position-Time Graph

September 28, 2020

It is easy to analyze and understand motion of an object if it is represented graphically. To draw graph of the motion of an object, its position at different times are shown on y-axis and time on x-axis.

#### Average Speed and Average Velocity

September 26, 2020

Speed during a certain interval of time can not be used to determine total distance covered in given time of the journey and also the time taken to cover the total distance of journey. It is because a body does not always travel equal distance in equal interval of time.

#### Velocity

September 24, 2020

When motion is along the shortest path, it is directed from the point of start to the point of finish. How fast this motion is determines the velocity. The velocity is the ratio of length of the shortest path (displacement) to the time taken.

#### Speed

September 22, 2020

The measure of how fast motion can take place is the speed. Speed can be defined as the distance traveled by a body in unit time.

#### Distance and Displacement

September 20, 2020

For a moving object two points are significant. One is the point of start or origin where from the object starts its motion and the other is the point where it reaches after certain interval of time. Points of start and destination are connected by a path taken by the object during its motion.