Answer:
500.3 Bq
Explanation:
From the formula;
0.693/t1/2 = 2.303/t log (Ao/A)
Where;
t1/12 = half life = 5 years
Ao = initial activity = 2000 Bq
0.693/5 = 2.303/10 log (2000/A)
0.1386= 0.2303 log (2000/A)
0.1386/0.2303 = log (2000/A)
0.6018 = log (2000/A)
(2000/A) = Antilog (0.6018)
(2000/A) = 3.9976
A = 2000/3.9976
A = 500.3 Bq
Answer:
a) S = 2.35 10³ J/m²2
,
b)and the tape recorder must be in the positive Z-axis direction.
the answer is 5
c) the direction of the positive x axis
Explanation:
a) The Poynting vector or intensity of an electromagnetic wave is
S = 1 /μ₀ E x B
if we use that the fields are in phase
B = E / c
we substitute
S = E² /μ₀ c
let's calculate
s = 941 2 / (4π 10⁻⁷ 3 10⁸)
S = 2.35 10³ J/m²2
b) the two fields are perpendicular to each other and in the direction of propagation of the radiation
In this case, the electro field is in the y direction and the wave propagates in the ax direction, so the magnetic cap must be in the y-axis direction, and the tape recorder must be in the positive Z-axis direction.
the answer is 5
C) The poynting electrode has the direction of the electric field, by which or which should be in the direction of the positive x axis
I believe the answer is c
