A muon is traveling at 0.4 c relative to a laboratory frame of reference. The sp
ID: 1439819 • Letter: A
Question
A muon is traveling at 0.4c relative to a laboratory frame of reference. The speed of the muon is doubled to 0.8c.
Part A
What happens to the momentum of the muon in the laboratory frame of reference?
Part B
What happens to the kinetic energy of the muon in the laboratory frame of reference?
Part C
What happens to the total energy of the muon in the laboratory frame of reference?
Explain your answers, thanks.
more than doubles. doubles increases by less than a factor of 2 stays the same. decreasesExplanation / Answer
A.)
given that relativistic momentum is p = gamma * m0 * v, where gamma is
1/sqrt(1 - (v^2/c^2)), m0 = rest mass, v = velocity
gamma is the proportion of the relativistic mass to the rest mass.
at 0.4c
P = 1/sqrt(1 - (v^2/c^2)) * m0 * v
P = 1.091 * m0 * 0.4c = 0.436c *m0
at 0.8c
P = 1/sqrt(1 - (v^2/c^2)) * m0 * v
P = 1.666 * m0 * 0.8c = 1.333c *m0
So it become roughly thrice of 0.4c
Momentum at 0.8c would be roughly 3 times that at 0.4c.
so it become more than double in laboratory frame of refrence.
B) K.E = 0.5 mv^2
given that relativistic momentum is p = gamma * m0 * v, where gamma is
1/sqrt(1 - (v^2/c^2)), m0 = rest mass, v = velocity
gamma is the proportion of the relativistic mass to the rest mass.
kinetic energy at 0.8c would be more than 4 times that at 0.4c.
kinetic energy become more than quadruples in laboratory frame of refrence
C.)
similarly energy become more than double in the laboratry frame of refrence