To solve the problem, it is necessary the concepts related to the definition of area in a sphere, and the proportionality of the counts per second between the two distances.
The area with a certain radius and the number of counts per second is proportional to another with a greater or lesser radius, in other words,
M,m = Counts per second
Our radios are given by
Therefore replacing we have that,
Therefore the number of counts expect at a distance of 20 cm is 19.66cps
Answer:
Thus the time taken is calculated as 387.69 years
Solution:
As per the question:
Half life of = 28.5 yrs
Now,
To calculate the time, t in which the 99.99% of the release in the reactor:
By using the formula:
where
N = No. of nuclei left after time t
= No. of nuclei initially started with
(Since, 100% - 99.99% = 0.01%)
Thus
Taking log on both the sides:
t = 387.69 yrs
Answer:
The magnitude and direction of the magnetic field is 93.63 T in negative x direction.
Explanation:
Given;
speed of the electron in positive y direction, v = 2.0 x 10⁵ m/s
magnetic force on the electron, F in negative z direction = 3.0 x 10⁻¹² N
The magnitude of the magnetic force is given by;
F = Qv x B
B = F / Qv
The direction of the magnetic field is is as;
Based on the direction of magnetic force (negative z direction), the charge will be directed into negative y-direction because electron is negatively charged. Thus, the direction of the magnetic field will be in the negative x-direction
Therefore, the magnitude and direction of the magnetic field is 93.63 T in negative x direction.