I think the same .
Why ?
Irrespective of the heat capacity of the hot object , it will start cooling down till it's temperature becomes equal to the room temperature .
Rate of Heat transfer is proportional to the temperature difference (fourth power) . It will be maximum initially and...
In the OP in part c) I have assumed energy to be kinetic energy in which case the momentum of proton was more and wavelength smaller .
But if I consider energy to be relativistic energy in part c) , then momentum of photon comes out to be less and wavelength of proton is longer .
I hope you...
Please confirm one thing .
What is your interpretation of the problem statement ?
Are you comparing
1) the time before and after the hot body is placed .
OR
2) the time after the hot body is placed till thermal equilibrium is achieved .
Don't you think we just need to consider whether the rate of heat transfer decreases or not ?
As the temperature of hot body decreases , rate of heat transfer decreases . As a consequence , the photons comprising the heat radiations should decrease with time .
Please have a relook at the OP...
Could you explain why my assumption that time after the hot body is placed is incorrect .
Don't you think wording of the question should have been " Has the number of photons increased ? " if the question wanted to compare the number before and after the hot body is placed ?
Homework Statement
Homework Equations
The Attempt at a Solution
No .
The number of photons should decrease . As the rate of heat transfer decreases with time , the net electromagnetic radiation from the hot body to the surroundings decrease .
Heat radiations are composed of photons ...
No :smile:
I asked because E = Pc doesn't involve vectors whereas in the OP direction of momentum vector was to be considered while relating to wavelength (energy ) .
In the relation E = Pc for a photon, are both the terms on RHS (momentum and speed ) treated as vectors and is it that a dot product is taken so as to get the energy term E ?
Are the two expressions equivalent ?
What should we put for P (momentum ) ?
Should it be mv ?
I am studying basics of photons , so I am quite hesitant to use mv for momentum for other particles as well .
I have .
But I thought this was obtained from the formula E2 = P2c2 + m02c4 by putting P = 0 .
I thought E = mc2 was valid for a particle at rest i.e for a particle having zero momentum .
Homework Statement
Homework Equations
The Attempt at a Solution
I am surely making some very silly mistake in this problem . Presuming linear momenta means magnitude of momentum , to me all four options look correct .
a) since wavelengths are same , energy is same which means momentum...
Homework Statement
Homework Equations
The Attempt at a Solution
de Broglie wavelength λ of a particle = h /P
a) since mass of proton is more than electron and speed is same , momentum of proton is more . De Broglie wavelength of proton will be less .
b) wavelengths will be same .
c)...
Homework Statement
Homework Equations
The Attempt at a Solution
This is an example given in the book . But I am just wondering whether the question itself is correct .
How can intensity of light emitted from Sun is given a constant ? Shouldn't 1400 be the power emitted from Sun ?
If...
While applying Faraday in the outer loop , what area should I use , area of the outer loop OR area of the outer loop minus area of the inner loop ?
@Charles Link , @cnh1995
Hi cnh1995 ,
Interesting !
You showed L = 0 and then chose option a) Did you mean option c) :smile: ?
What is the mistake in the reasoning in latter part of post#26 ?
Please refer to post#22 .
How ?
Is it because windings are reversed in each layer such that if first winding is CW , next is ACW , then CW , such that flux from any two neighbouring turns cancel each other . The net flux for the complete solenoid being zero , making L2 = 0 ?