Grade 109 grade science
How can light have momentum as it does not have mass and p=mv
How can light have momentum as it does not have mass and p=mv
1 Answer
Saurabh Kumar
The theory of Special Relativity, proved in 1905 (or rather the 2nd paper of that year on the subject) gives an equation for the relativistic energy of a particle;
E2=(m0c2)2+p2c2
where m0 is the rest mass of the particle (0 in the case of a photon). Hence this reduces to E=pc. Einstein also introduced the concept of relativistic mass (and the related mass-energy equivalence) in the same paper; we can then write
mc2=pc
where m is the relativistic mass here, hence
m=p/c
In other words, a photon does have relativistic mass proportional to its momentum.
E2=(m0c2)2+p2c2
where m0 is the rest mass of the particle (0 in the case of a photon). Hence this reduces to E=pc. Einstein also introduced the concept of relativistic mass (and the related mass-energy equivalence) in the same paper; we can then write
mc2=pc
where m is the relativistic mass here, hence
m=p/c
In other words, a photon does have relativistic mass proportional to its momentum.
Other Related Questions on 9 grade science
Prepare a plant cell model by household materials. Like rice ,plastic,cardboard.etc."*"
Prepare a plant cell model by household materials. Like rice ,plastic,cardboard.etc."*"
9 grade science
Last Activity: 9 Months ago
List the point of difference between Homogeneous and Heterogeneous mixtures
List the point of difference between Homogeneous and Heterogeneous mixtures
9 grade science
Last Activity: 0 Years ago