Where Does the Formula p=mv Originate From in Physics?

  • Thread starter Cheman
  • Start date
In summary, momentum is one of the fundamental concepts in physics that describes the physical state of a particle. It is purely empirical and is introduced through experimental evidence. According to Newton's laws, an isolated particle has a fixed momentum and changes in momentum are caused by interactions with forces. This definition is only valid in classical mechanics and is not applicable in quantum or relativistic theories.
  • #1
Cheman
235
1
What exactly IS momentum? How do we arrive at the formula "p= mv"? Where does that formula come from - is it purely empirical or is there something more meaningful to it?

Thanks. :smile:
 
Physics news on Phys.org
  • #2
Cheman said:
What exactly IS momentum? How do we arrive at the formula "p= mv"? Where does that formula come from - is it purely empirical or is there something more meaningful to it?

Thanks. :smile:

It's one of the fundamental concepts in physics.It's introduced purely experimental.It is,alonside position,one variable which describes,at classical level,the physical state of the particle.According to the first Newton's law,an isolated particle has a specific fixed momentum.If it's at rest in an inertial reference system,its momentum is zero.If not,not.Changes of momentum automatically imply that the particle suffered an interraction (and viceversa)described at classical level by forces.Newton's second law should always be stated mathematically by:[itex] \frac{d(m\vec{v})}{dt} [/itex] is equal to the vector sum of all forces acting on the particle.It can be interpreted via "cause-effect logics".
The definiton u gave belongs only to the realm of classical (nonrelativistic)mechanics of pointlike particles in the Newton's approach.
At quantum + relativistic level,it's not valid anymore,because both theories deal with other notion of momentum,the canonical momentum (see Hamilton formalism of classical dynamics).

Regards,

Daniel.
 
Last edited:

FAQ: Where Does the Formula p=mv Originate From in Physics?

Where does the equation p=mv come from?

The equation p=mv comes from the principle of conservation of momentum, which states that in a closed system, the total momentum before an event must be equal to the total momentum after the event. This is a fundamental law in physics and is used to describe the motion of objects.

How is the equation p=mv derived?

The equation p=mv is derived from Newton's second law of motion, which states that the force acting on an object is equal to the mass of the object multiplied by its acceleration. By rearranging this equation, we can obtain p=mv, where p is momentum, m is mass, and v is velocity.

What is the significance of the equation p=mv?

The equation p=mv is significant because it allows us to quantitatively describe the motion of objects and predict their behavior. It is also a crucial component of many other equations and principles in physics, such as work and energy.

Can the equation p=mv be applied to all objects?

Yes, the equation p=mv can be applied to all objects, as long as they have mass and velocity. This includes both macroscopic objects like cars and buildings, as well as microscopic particles like atoms and electrons.

Is there a difference between momentum and velocity?

Yes, momentum and velocity are two different quantities. Velocity is a vector quantity that describes the speed and direction of an object's motion, while momentum is a vector quantity that describes the quantity of motion an object possesses. In other words, velocity tells us how fast an object is moving, while momentum tells us how hard it is to stop the object.

Similar threads

Replies
6
Views
2K
Replies
11
Views
12K
Replies
4
Views
3K
Replies
8
Views
2K
Replies
1
Views
2K
Replies
28
Views
2K
Replies
6
Views
1K
Back
Top