Answer:
(a) 62.69 nJ/m^3
(b) 1015.22 μJ/m^3
Explanation:
Electric field, E = 119 V/m
Magnetic field, B = 5.050 x 10^-5 T
(a) Energy density of electric field = 
= 6.269 x 10^-8 J/m^3 = 62.69 nJ/m^3
(b) energy density of magnetic field = 

= 1.01522 x 10^-3 J/m^3 = 1015.22 μJ/m^3
If the length and linear density are constant, the frequency is directly proportional to the square root of the tension.
Answer:
57,42 KJ
Explanation:
By a isobaric proces, the expresion for the works in the jpg adjunt. Then:
W = Pa(Vb - Va) = Pa*Vb - Pa*Va ---(1)
By the ideal gases law: PV=RTn
Then, in (1): (remember Pa = Pb)
W = R*Tb*n - R*T*an = R*n*(Tb - Ta) --- (2)
Since we have 1 Kg air: How much is this in moles?
From bibliography: 28.96 g/mol
Then, in 1 Kg (1000 g) there are:
n = 34,53 mol
Finally, in (2):
W = (8,3144 J/K.mol)*(34,53 mol)*(500K - 300K) = 51 419,9 J ≈ 57,42 KJ
The number of protons determines the element. Many elements also have many isotopes. Such as carbon-14 Carbon-12 and carbon-10.