Question

Free Answer Questions: 5 points/problem) Make sure to draw a diagram, identify relevant physical quantities, write down the appropriate principles/equations, execute the calculation, make sure to show your work, and evaluate your answer. 11. Circle your final answers. A muon is created by a cosmic-ray interaction at an altitude of 60 km (6.36 μs in SR unit). After its creation, the muon hurtles downward at a speed of 0.99 (99% of the speed of the light), as measured by a ground-based observer. (a) What is the time for the muon to reach the ground for the ground-based observer? (b) What is the time interval for the muon to reach the ground measured by the muon's internal clock? (c) Muons are unstable, decaying after a short time into lighter particles. Muons at rest in a laboratory has a half-life of about 1.52 μs, which means that if 100 muons are created, the number will become ½ (50 muons) after 1.52 μs. Suppose 1000 muons are created initially, do you expect more or less than 500 muons to reach the ground? Why?

Answer 1

(A)

(C) Since the time taken(Part A) is way more thant the half life of the muons, the number of muons will be less than half. That is, the number of muons will be less than 500 within the first 1.52us of its 202us journey