You are a health physicist and you find an unknown contaminant that proves to be a pure beta emitter. To try to identify the contaminant, you attempt to determine the maximum energy of the beta rays. You use a GM tube with a thin (0.1 mm, ?=2.7 g/cm^3) end window. You find that 1.74 mm stops all of the beta particles. The distance between the sample and the counter is 2 cm.
a. What is the energy of the beta particle?
b. What do you think the contaminant is?
a.) Range used for the Absorption of beta rays on the GM tube = Density* Distance = 2.7*0.174= 0.47 g/cm^2
Range = 0.47 ...
The solution includes calculations for the energy of a beta particle as well as the process involving finding an unknown contaminant (which is a pure beta emitter).
Calculate the fund's beta and required rate of return.
Alcoa's Inc.'s Pension Fund holds 4 stocks. The market's required rate of return is 6% and the risk free rate is 2%.
Stock Investment Beta
A $300,000 1.75
B $500,000 -0.75
C $1,000,000 1.05
D $500,000 0.75
a. What is this fund's beta?
b. Calculate the required rate of return.