## Saturday, March 4, 2017

### Newton's First and Second Law of Motion Video Lesson

Newton's first and second law are helpful in understanding translatory motion. Newton's first law explains the concept of inertia. Any  body has the property of continuing its own state of rest or motion when no external force is acting on the body. This property is called inertia. This itself is called first law of motion. Body can have inertia of rest,motion and direction.

Inertia of rest is the property of body due to which the body continue its state of rest until no external force is acting on the body. We can experience it in daily life. Consider a person in standing position that is in the  in a vehicle that is at rest.When the bus suddenly starts, the connected part of the person with the vehicle that are legs starts moving. But the upper part of the body tries to continue in  the state of rest due to inertia of rest. Thus the lower part of the body moves and the upper part stays there it self. So he fell like he got a jerk and fell like falling back. it is due to inertia of rest. The same can be explained with inertia of rest and direction. A Video lesson about the first law is shown below for your reference.

Newton's Second Law of motion

Newton's second law of motion is about force. Force is a physical quantity that changes or tries to change the state of the body. Force is defined as the rate of change of momentum. If a body is having a constant mass, then force can be defined as the product of mass and acceleration of the body.  Force is a vector that has both magnitude and direction and it is a vector quantity. The direction of the force is similar to the acceleration. It is explained in the video lesson below.

Resultant force and acceleration

When there is a resultant force acting on a body, then the body velocity gets changed and hence it will have some acceleration. If there are multiple force acting on a body, we shall find the effective force or resultant force using vector laws of addition. If there is no resultant force acting on a body, the body will be either moving with a constant velocity or in the state of rest basing on its previous condition. We can find the resultant force acting on a body as shown in the video lesson below.

Related Posts

Newton Law of Inertia and Newton law of Force an Introduction