- #1
StillNihilist
- 6
- 0
I have a few questions concerning mass that I'm hoping some kind soul more knowledgeable than myself can answer for me. Most of these concern mass energy equivalence, although two, I think, are classical questions that I have not even had to consider for several years (although they just passed me through modern physics with an A about a week ago, scary). If I should break this post in two and post the more classical questions in the other forum, please let me know.
1. Say I have some object, for example let's say a baseball (or an atom w/e). Then let's say, from my frame of reference the ball is stationary. Then from what I've learned I would say that the energy of the ball is related to its mass by E = mc^2. Now if I think about it, the ball is composed of a lot of electrons, protons, and neutrons, and none of these are at rest. Does this mean that the sum of the kinetic and potential energies of all of these particles would be equal to mc^2? How do values measured in different 'levels of scale' relate to one another when looking at an object/system?
2. This is related to question 1. If you say an object is 'at rest' with respect to some observer, does that just mean its center of mass has fixed space coordinates with respect to that observer or does it mean something else (since the individual components of the objects are not at rest)?
3. In regards to "mass-energy equivalence", if I take an object and heat it up, does its mass increase? Let's say I have a sealed box full of gas. If I heat the gas up will the mass of the system be greater? Would it weigh more on a hypothetical perfect accuracy scale? On that note, if I trapped light in a box, would the box with light trapped in it have more mass than an identical box without light trapped in it? I've read the FAQ, and I'm still a little fuzzy on what 'effective mass' is for light, as light has 0 rest mass.
4. This is related to question 3. If a system having more energy implies that it has more mass, does this mean that if I had an isolated system of two particles each with nonzero mass and zero charge, then if the objects were further away the system would have more mass than if the objects were closer together since there would be more gravitational potential energy? If so, how is that mass to be interpreted? If not, why not?
5. If light has some sort of "effective mass", since it has momentum, can you apply a force to light? I'm thinking the answer is 'no' as light, I think always has 0 acceleration meaning that no force is ever applied to it. However I'm not sure about this, I mean can light rotate? On that note if a force cannot be applied to light, then wouldn't that mean it's momentum would have to be an unchanging constant as F = dp/dt and F = 0 (in this case)?
Any help, information, or even redirection to where it can be obtained, would be extremely appreciated.
Thank you for your time and consideration.
StillNihilist
1. Say I have some object, for example let's say a baseball (or an atom w/e). Then let's say, from my frame of reference the ball is stationary. Then from what I've learned I would say that the energy of the ball is related to its mass by E = mc^2. Now if I think about it, the ball is composed of a lot of electrons, protons, and neutrons, and none of these are at rest. Does this mean that the sum of the kinetic and potential energies of all of these particles would be equal to mc^2? How do values measured in different 'levels of scale' relate to one another when looking at an object/system?
2. This is related to question 1. If you say an object is 'at rest' with respect to some observer, does that just mean its center of mass has fixed space coordinates with respect to that observer or does it mean something else (since the individual components of the objects are not at rest)?
3. In regards to "mass-energy equivalence", if I take an object and heat it up, does its mass increase? Let's say I have a sealed box full of gas. If I heat the gas up will the mass of the system be greater? Would it weigh more on a hypothetical perfect accuracy scale? On that note, if I trapped light in a box, would the box with light trapped in it have more mass than an identical box without light trapped in it? I've read the FAQ, and I'm still a little fuzzy on what 'effective mass' is for light, as light has 0 rest mass.
4. This is related to question 3. If a system having more energy implies that it has more mass, does this mean that if I had an isolated system of two particles each with nonzero mass and zero charge, then if the objects were further away the system would have more mass than if the objects were closer together since there would be more gravitational potential energy? If so, how is that mass to be interpreted? If not, why not?
5. If light has some sort of "effective mass", since it has momentum, can you apply a force to light? I'm thinking the answer is 'no' as light, I think always has 0 acceleration meaning that no force is ever applied to it. However I'm not sure about this, I mean can light rotate? On that note if a force cannot be applied to light, then wouldn't that mean it's momentum would have to be an unchanging constant as F = dp/dt and F = 0 (in this case)?
Any help, information, or even redirection to where it can be obtained, would be extremely appreciated.
Thank you for your time and consideration.
StillNihilist