Author Question: A radiometer has two square vanes (each measuring 1.0 cm by 1.0 cm), attached to a light horizontal ... (Read 172 times)

cookcarl

  • Hero Member
  • *****
  • Posts: 539
A radiometer has two square vanes (each measuring 1.0 cm by 1.0 cm), attached to a light horizontal cross arm, and pivoted about a vertical axis through the center, as shown in the figure.
 
  The center of each vane is 6.0 cm from the axis. One vane is silvered and it reflects all radiant energy incident upon it. The other vane is blackened and it absorbs all incident radiant energy. An electromagnetic wave with an intensity of 0.30 kW/m2 is incident normally upon the vanes. What is the electromagnetic power absorbed by the blackened vane? (c = 3.00  108 m/s,
  0 = 4  10-7 T  m/A, 0 = 8.85  10-12 C2/N  m2)
 
  A) 0.030 W
  B) 0.040 W
  C) 0.050 W
  D) 0.060 W
  E) 0.090 W

Question 2

Near the earth the intensity of radiation from the sun is 1.35 kW/m2. What volume of space in this region contains 1.0 J of electromagnetic energy? (c = 3.0  108 m/s, 0 = 4  10-7 T  m/A, 0 = 8.85  10-12 C2/N  m2)
 
  A) 4.5  10-6 m3
  B) 3300 m3
  C) 7.4  10-4 m3
  D) 1400 m3
  E) 220,000 m3



johnharpe

  • Sr. Member
  • ****
  • Posts: 338
Answer to Question 1

Answer: A

Answer to Question 2

Answer: E



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

Many medications that are used to treat infertility are injected subcutaneously. This is easy to do using the anterior abdomen as the site of injection but avoiding the area directly around the belly button.

Did you know?

Asthma-like symptoms were first recorded about 3,500 years ago in Egypt. The first manuscript specifically written about asthma was in the year 1190, describing a condition characterized by sudden breathlessness. The treatments listed in this manuscript include chicken soup, herbs, and sexual abstinence.

Did you know?

Most strokes are caused when blood clots move to a blood vessel in the brain and block blood flow to that area. Thrombolytic therapy can be used to dissolve the clot quickly. If given within 3 hours of the first stroke symptoms, this therapy can help limit stroke damage and disability.

Did you know?

Despite claims by manufacturers, the supplement known as Ginkgo biloba was shown in a study of more than 3,000 participants to be ineffective in reducing development of dementia and Alzheimer’s disease in older people.

Did you know?

Pregnant women usually experience a heightened sense of smell beginning late in the first trimester. Some experts call this the body's way of protecting a pregnant woman from foods that are unsafe for the fetus.

For a complete list of videos, visit our video library