• Support PF! Buy your school textbooks, materials and every day products Here!

How long does a moun live during a measurement

  • #1
672
0

Homework Statement


A muon with a kinetic energy of 200 ± 0.05 MeV
is produced in a linear accelerator. The rest
mass of the muon is 106 MeV/c2.
(a) Calculate the speed of the muon (in units of c),
(b) Calculate the linear momentum (in units of eV/c),
(c) How long does it live during the measurement?
(d) Find the lifetime of the muon.
(e) What is the distance traveled by muon in laboratory
before it disappears (use c = 3 x 108 m/s)? Could
this distance be measured?
(f) For identifying a muon what method do you think
that is better: (1) based on measurements of energy
or (2) based on measurements of distance? Why?

I am having trouble with part c


Homework Equations


(1 stands for naught)
E = E1 + K
deltaE dot deltaT = h (I dont understand this equation)
deltaT = h/deltaE


The Attempt at a Solution


I found this and the solution online I understand part a and b then answers are respectivley v=.938c and p=287MeV/c. It is part c that im struggling with this is what my instructor does he says deltaE dot deltaT = h which isnt on my equation sheet so im not sure about this. Then he states E = K + E1 remains constant, then sets deltaE=deltaK = .1MeV I think I understand where he got the equality part and I think I get how he got .1 I assume he did this .05-(-.05) = .1 = deltaK = deltaE. But I am not sure as to why he did this. Then deltaT = h/deltaE = (6.58e-16 eV.s)/(1e5 eV) = 6.58e-21s. How the heck did he obtain 6.58e-16 I am confused?
 

Answers and Replies

  • #2
672
0
Ouch! no replies yet very weird I guess maybe I was confusing or something.
 
  • #3
6,054
390
The equation you don't understand seems to be the uncertainty principle for energy and time.
 
  • #4
672
0
lol after looking up the uncertainty principle I agree thats what it is but I really need to know where the .1 and 6.58e-16 came from?
 
  • #5
6,054
390
.1 comes from the uncertainty of energy. 6.58e-16 is Planck's constant in eV.s.
 

Related Threads for: How long does a moun live during a measurement

Replies
2
Views
1K
  • Last Post
Replies
6
Views
9K
  • Last Post
Replies
12
Views
2K
Replies
31
Views
5K
Replies
5
Views
1K
  • Last Post
2
Replies
30
Views
3K
Replies
2
Views
427
Replies
2
Views
1K
Top