Calculating Muon Decay in Relativity: A Scientific Analysis

AI Thread Summary
The discussion revolves around calculating muon decay in the context of relativity. A muon, with a rest lifetime of 2.20 x 10^-6 seconds, is analyzed for its behavior at a speed of 0.99c. According to Newtonian mechanics, it would travel approximately 653.4 meters before decaying. However, in the Earth's frame of reference, the muon's lifetime extends to 1.56 x 10^-5 seconds, allowing it to travel about 4633.2 meters. The participant expresses initial uncertainty about part (c) but later confirms the calculations are correct.
student07
Messages
36
Reaction score
1

Homework Statement


A muon has a lifetime of 2.20 x 10^-6 s when at rest, after which time it decays into other particles.
a) If the muon was moving at 0.99c, how far would it travel before decaying into other particles, according to Newtonian mechanics?
b) How long would the muon last, according to an observer in Earth's frame of reference who viewed the muon moving at 0.99c?
c) How far would the muon actually travel, when viewed moving at 0.99c?

2. The attempt at a solution
a) 0.99c(3 x 10^8c) = 2.97 x 10^8
(2.97 x 10^8 m/s)(2.2 x 10^-6 s) = 653.4 m

b) Δtm = Δts/√(1-v^2/c^2)
Δtm = 2.2 x 10^-6 s / √(1-(0.99c)^2/c^2)
= 2.2 x 10^-6 s / √ (1 - 0.9801) = 1.56 x 10^-5 s

c) (2.97 x 10^8 m/s)(1.56 x 10^-5 s) = 4633.2 m

Not sure about c) any suggestions are appreciated thank you
 
Physics news on Phys.org
Look good to me! :smile:

Is there something about part (c) that makes you unsure?
 
Actually after giving it another look I got around it so thanks for your confirmation
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top