How do fields carry momentum?
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How do fields carry momentum?
Electrostatic and magnetostatic fields consist, in the quantum picture, of a huge number of virtual photons flying back and forth. Now, each of these photons carries a certain amount of momentum. They must, because they will impart a force on the charged particles that absorb or emit them.
Does a magnetic field have momentum?
The answer is that if you have a magnetic field and some charges, there will be some angular momentum in the field. It must have been put there when the field was built up. When the field is turned off, the angular momentum is given back.
Can electric fields carry momentum?
An electromagnetic wave carries momentum in the direction of propagation; when it hits an absorber, this momentum is transferred in the form of the pressure of light. A charged capacitor in the presence of an external magnetic field carries electromagnetic momentum even though nothing is moving.
Does electricity have momentum?
Yes, moving charges do have momentum. But it is inconsequential in most circuits.
Can momentum be stored?
Momentum must be conserved, linear and angular. There is no reason to require flow only for angular momentum. A spring has momentum during compression. It does not require momentum flow while compressed, it is stored.
How do you describe momentum?
Momentum can be defined as “mass in motion.” All objects have mass; so if an object is moving, then it has momentum – it has its mass in motion. In terms of an equation, the momentum of an object is equal to the mass of the object times the velocity of the object.
What is momentum in fluid?
The momentum of a fluid is defined to be ρu, per unit volume. Newton’s second law of motion states that momentum is conserved by a mechanical system of masses if no forces act on the system. We are thus in a position to use (2.14), where the “sources and sinks” of momentum are forces.
Which expression gives the momentum of an object?
In symbols, linear momentum is expressed as p = mv. Momentum is directly proportional to the object’s mass and also its velocity. Thus the greater an object’s mass or the greater its velocity, the greater its momentum.