Chronon

  So far, we have come across first and second law of motion. In first law of motion, we learnt that every object tends to remain in its state of motion, until an external force is compelled to change the state. In second low of motion, we described that the rate of change of momentum of an object is proportional to the applied unbalanced force in the direction of force. From first and second law of motion, we know that if an object is in state of rest it will stay in that state until an external force is applied. When an external force is applied, now this object has a momentum. What if the object A1 with momentum P1 collides with an object A2 possessing momentum P2? How momentum will change, distribute, or will be lost after collision?   In this situation, let's suppose the Collison is a head on collision. From the collision theory, which will be discussed in our upcoming blogs, we know that in a head on collision, no amount of velocity is lost. When velocity is conserve...

  As we discussed in previous blog, the first law of motion indicates that when an unbalanced external force acts on an object, its velocity changes, that is, the object gets an acceleration. From our everyday life observation, we know that, during the game of table tennis if the ball hits a player, it does not hurt him. On the other hand, when a fast-moving cricket ball hits a spectator, it may hurt him. A truck at rest does not require any attention when parked along a roadside. But a moving truck, even at very low speeds, may harm a person standing in its path. A small mass, such as a bullet may kill a person when fired from a gun. These observations suggest that this kind of impact is produced by combination of mass and velocity in the object. In the language of physics, this combination of mass and velocity is known as momentum. Momentum is defined as the product of mass and velocity of an object possessing a magnitude and a direction. It is denoted by 'P' and mathematical...

  We have observed that, if we put an object in motion it comes in state of rest. But if we put any object in state of rest it remains in that state. For example, if we throw a ball upward or roll it on the ground, it will ultimately come in the state of rest, but if the ball is already in the state of rest, it does not start moving on its own. In our previous episode we discussed that, every object tends to stay in its state until and external force compelled to change the state. So how this ball is changing its state of motion on its own. A simple answer is, there are always some kind of invisible forces in action. For example, when the ball is thrown in the sky, gravitational force is in action and when the ball is rolling on the ground, frictional force is in action. Thus, the ball is coming back to its rest state. We will discuss these two forces in our upcoming episodes.   For a better understanding, let us suppose an object is in the space and no gravitational force...

  From many centuries the problem of motion and its causes had puzzled scientists and philosophers until Galileo and Newton developed entirely different approach to understand motion. We have observed that, whenever an object is in motion it involves a form of hit, push or pull. In physics, a force is defined as any interaction such as hit, push, or pull, when unopposed, will change the state of an object. Hence, a force can put a moving object into state of rest or vice versa and a force can also change the shape, size, speed, velocity, or direction of motion. In our upcoming episodes we will discuss, to change the state of an object, either it is in state of motion or state of rest, we need a net external force. Now let us understand the concept of net force. Net force is the vector sum of forces acting on a particle or body. The net force is a single force that replaces the effect of the original forces on the particle's state. It gives the particle the same acceleration as al...