define newton's first law of motion and explain how it leads us to concept of inertia and definition of force

Question

define newton's first law of motion and explain how it leads us to concept of inertia and definition of force?

Answer 1

If you lift a 100 pound weight with only 50 pounds of force, the weight will remain on the floor because of inertial (it is pulling down more by gravity than you are pulling up). Although you may be greatly exerting yourself, you have added no energy to the weight. If you now lift with an upward force of 101 pounds, you overcome the downward force of the weight and it rises. Importantly you are now adding potential energy to the weight. Lift the weight one foot and you have added 100 foot-pounds of potential energy by doing work (force times a distance) on the weight. We know that a pendulum can convert potential energy (height) to kinetic energy (motion) continuously until stopped by friction (that converts the energy to heat and sound, etc.). Therefore, a body will remain at rest until you add energy to it and it will then remain in motion until the energy is removed again. Energy is added when a force acts on the weight for a distance and energy is removed when the weight acts as a force moving a resistance a distance. This is simple in a frictionless (ideal) system but in fact friction often applies a force to the weight removing its energy in the form of heat. Hope that helps a little.

Answer 2

Define Law Of Inertia

Answer 3

First law of motion:-A body tends to be in the state of rest or motion unless and until an external force acts on it.

EXPLANATIONS:-Suppose you roll a ball on the road, according to law of motion it should continue rolling on the road. But it does not happen so. Because here an external force acts that is friction so the ball stops rolling. If by any means we can remove the friction then it will obey the Newtons first law of motion.

INERTIA:- The tendency of the body to resist any kind of change.

EXPLANATIONS:-It implies that if a body is in motion it will try to remain in the state of motion. e.g people traveling in a bus are in the state of the motion, when bus is suddenly stopped, people experience a jerk in the forward direction. Same is the case when the body is in the rest condition.

FORCE:-It is the product of mass and acceleration
Inertia is something which RESIST changes. This RESIST is nothing but the FORCE.

Answer 4

Newton's first law: law of inertia

Lex I: Corpus omne perseverare in statu suo quiescendi vel movendi uniformiter in directum, nisi quatenus a viribus impressis cogitur statum illum mutare.

An object at rest will remain at rest unless acted upon by an external and unbalanced force . An object in motion will remain in motion unless acted upon by an external and unbalanced force.

This law is also called the law of inertia or Galileo's principle.

The net force on an object is the vector sum of all the forces acting on the object. Newton's first law says that if this sum is zero, the state of motion of the object does not change. Essentially, it makes the following two points:

* An object that is not moving will not move until a net force acts upon it.

* An object that is in motion will not change velocity (including stopping) until a net force acts upon it.

The first point seems relatively obvious to most people, but the second may take some thinking through, because we have no experience in every-day life of things that keep moving forever (except celestial bodies). If one slides a hockey puck along a table, it doesn't move forever, it slows and eventually comes to a stop. But according to Newton's laws, this is because a force is acting on the hockey puck and, sure enough, there is frictional force between the table and the puck, and that frictional force is in the direction opposite the movement. It is this force which causes the object to slow to a stop. In the absence of such a force, as approximated by an air hockey table or ice rink, the puck's motion would not slow.

Although the 'Law of Inertia' is commonly attributed to Galileo, Aristotle wrote the first known description of it:

[N]o one could say why a thing once set in motion should stop anywhere; for why should it stop here rather than here? So that a thing will either be at rest or must be moved ad infinitum, unless something more powerful get in its way. [ Physics 4.8 ]

However, a key difference between Galileo's idea from Aristotle's is that Galileo realized that force acting on a body determines acceleration, not velocity. This insight leads to Newton's First Law - no force means no acceleration, and hence the body will continue to maintain its velocity.

The Law of Inertia apparently occurred to many different natural philosophers independently. Inertia of motion was described in the third century BCE in the Mo Tzu, a collection of Chinese philosphical texts, and the 17th century philosopher René Descartes also formulated the law, although he did not perform any experiments to confirm it.

There are no perfect demonstrations of the law, as friction usually causes a force to act on a moving body, and even in outer space gravitational forces act and cannot be shielded against, but the law serves to emphasize the elementary causes of changes in an object's state of motion: forces.

Answer 5

Newton's First Law of Motion goes something like this : "A body tends to remain its state of rest or that of uniform motion along a straight line,unless compelled to change by an external unbalanced force."
Inertia is the tendency of a body to resist any change in its motion and is measured by its mass.
Momentum is the product of mass and velocity [m x v] and the rate of change of momentum [m x v - u/t = m x acceleration] is force.

Answer 6

Forget about the cart, just focus on the three blocks. The inertia of the blocks results in them wanting and trying to keep moving, regardless of what happens to the cart which is carrying them. It is indeed a demonstration of Newton's First Law. The blocks keep moving since there is no external force acting on them. The external force is acting on the cart only.