DO NOT USE THIS TAG if a more descriptive tag applies.

learn more… | top users | synonyms

0
votes
1answer
12 views

Rate of change in size:Moving Objects

Is there a way of calculating the rate at which an object decreases/increases in size relative to the observer.For example,if a bus(4m wide) is moving away from a stationary observer at the rate of ...
1
vote
0answers
126 views

Scales and Hooke's Law

Bob weighs $B$ kg and when he steps on a scale, the spring inside gets compressed by $c$ meters. Assuming the scale obeys Hooke's Law, if Alice weights $A$ kg, how much work is done compressing the ...
0
votes
0answers
33 views

Chemical potential and origin of pressure in a solid

Pressure of a gas is related to the rate of change of momentum of the particles; the temperature is the mean kinetic energy of the particles. Can the chemical potential be given a similar physical ...
-3
votes
0answers
62 views

Why photon have zero rest mass?

If photon have zero rest mass then the term E=hf should also be zero because if rest mass is zero then relativistic mass is also zero and so on by Einstein mass energy relation energy shoud be zero ...