Problem 34.42 Part A At one instant, the electric and magnetic fields at one poi

Question

Problem 34.42 Part A At one instant, the electric and magnetic fields at one point of an electromagnetic wave are E (220i 300 j - 50k)V/m and B = (7.81-7.7 j + ak)B0 What is the value of a? Express your answer using two significant figures. Submit My Answers Give Up Part B What is the value of Bo? Express your answer using two significant figures AT Submit My Answers Give Up Part C What is the Poynting vector at this time and position? Find the -component. Express your answer to two significant figures and include the appropriate units SValue Units Submit My Answers Give Up

Explanation / Answer

A] we know that E.B = 0

220*7.8 -300*7.7 - 50a = 0

a = [ 220*7.8 -300*7.7]/50 = -11.88 = -12 answer

B] |B| = E/c = sqrt(220^2+300^2+50^2) /3e8 = 1.251e-6

B0 = 1.251e-6/sqrt(7.8^2+7.7^2+11.88^2) = 0.077*10^-6 T = 0.077 uT answer

c] poynting vector S = 1/u0 E x B

Sx = 1/[4pi *10^-7] *(300*12 - 50*7.7)*7.7e-8 = 2.0*10^2 W/m^2

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.