Question

Question 10 of 10

2 Points
What is the energy of an electromagnetic wave that has a wavelength of
4.0 x 102 m? Use the equation E-
Intion hc
, where hc = 1.99 x 10-25 J•m.
O A. 8.0 x 10-23
O B. 2.0 × 1027
O C. 6.0 x 1025 J
O D. 5.0 × 10-28 J

Answer 1

Answer: D.
`5.0(10)^(-38) J`

Step-by-step explanation:

The energy
`E` of an electromagmetic wave is given by:

`E=(hc)/(\lambda)`

Where:

`h=6.626(10)^(-34)J.s` is the Planck constant

`c=3(10)^(8) m/s` is the speed of light in vacuum

Then
`hc=1.99 (10)^(-25)Jm`

`\lambda=4.0(10)^(12) m` is the wavelength

Solving:

`E=(1.99 (10)^(-25)Jm)/(4.0(10)^(12) m)`

`E=5.0(10)^(-38) J`