Asmall helium-neon laser emits red visible light with a power of 5.80 mw in a beam that has a diameter of 2.40 mm . part a what is the amplitude of the electric field of the light? express your answer with the appropriate units. emax e max = nothing nothing request answer part b what is the amplitude of the magnetic field of the light? bmax b max = nothing t request answer part c what is the average energy density associated with the electric field? express your answer with the appropriate units. ue u e = nothing nothing request answer part d what is the average energy density associated with the magnetic field? express your answer with the appropriate units. ub u b = nothing nothing request answer part e what is the total energy contained in a 1.00-m length of the beam? express your answer with the appropriate units. u u = nothing nothing request answer provide feedback

A) 983.2 V/m

First of all, we need to find the intensity of the laser light:

where

is the power

A is the area

the diameter is 2.40 mm, so the radius is 1.20 mm (), therefore the area is

And the intensity is

The amplitude of the electric field is related to the intensity by

where

c is the speed of light

is the vacuum permittivity

E is the amplitude of the electric field

Solving for E, we find

B)

The amplitude of the magnetic field is given by

where

E = 983.2 V/m is the amplitude of the electric field

c is the speed of light

Substituting,

C)

The average energy density associated with the electric field is

where

is the vacuum permittivity

E = 983.2 V/m is the amplitude of the electric field

Substituting,

D)

The average energy density associated with the magnetic field is

where

is the vacuum permeability

is the amplitude of the magnetic field

Substituting,

In fact, the average energy density associated with the electric field in an electromagnetic wave is equal to the average energy density associated with the magnetic field.

E)

The area of the beam is (calculated at point A)

The lenght of the beam is

L = 1.00 m

So the volume of the beam is

The total energy density is the sum of the energy density of the electric and magnetic field:

so, the total energy in the beam will be:

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.

the right answer is 0.3 meters per second