Answer:
a is the answer to the question
Answer:
1.2826 x 10^-13 m
Explanation:

Here, k be the kinetic energy and m be the mass
K = 50 KeV = 50 x 1.6 x 10^-16 J = 80 x 10^-16 J
m = 1.67 x 10^-27 kg

λ = 1.2826 x 10^-13 m
Answer:
The rate of transfer of heat is 0.119 W
Solution:
As per the question:
Diameter of the fin, D = 0.5 cm = 0.005 m
Length of the fin, l =30 cm = 0.3 m
Base temperature, 
Air temperature, 
k = 388 W/mK
h = 
Now,
Perimeter of the fin, p = 
Cross-sectional area of the fin, A = 
A = 
To calculate the heat transfer rate:

where

Now,

The instrument is a Geiger counter and is used to measure radioactive level around people's bodies.