« previous next »

Author Question: Star A has a radius of 200 000 km and a surface temperature of 6 000 K. Star B has a radius of 400 ... (Read 32 times)

armygirl

  • Hero Member
  • *****
  • Posts: 556
on: Jul 28, 2018
Star A has a radius of 200 000 km and a surface temperature of 6 000 K. Star B has a radius of 400 000 km and a surface temperature of 3 000 K. The emissivity of both stars is the same. What is the ratio of the rate of energy radiated by Star A to that of Star B?

Question 2

In braking an automobile, the friction between the brake drums and brake shoes converts the car's kinetic energy into heat. If a 1 500-kg automobile traveling at 30 m/s brakes to a halt, how much does the temperature rise in each of the four 8.0-kg brake drums? (The specific heat of each iron brake drum is 448 J/kg/C).


ally

  • Sr. Member
  • ****
  • Posts: 331
Reply #1 on: Jul 28, 2018
Answer to Question 1

4

Answer to Question 2

47C


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

Malaria was not eliminated in the United States until 1951. The term eliminated means that no new cases arise in a country for 3 years.

Did you know?

Chronic necrotizing aspergillosis has a slowly progressive process that, unlike invasive aspergillosis, does not spread to other organ systems or the blood vessels. It most often affects middle-aged and elderly individuals, spreading to surrounding tissue in the lungs. The disease often does not respond to conventionally successful treatments, and requires individualized therapies in order to keep it from becoming life-threatening.

Did you know?

Russia has the highest death rate from cardiovascular disease followed by the Ukraine, Romania, Hungary, and Poland.

Did you know?

The effects of organophosphate poisoning are referred to by using the abbreviations “SLUD” or “SLUDGE,” It stands for: salivation, lacrimation, urination, defecation, GI upset, and emesis.

Did you know?

The most destructive flu epidemic of all times in recorded history occurred in 1918, with approximately 20 million deaths worldwide.

Enzyme activity is affected substantially by temperature Enzyme activity is affected substantially by temperature
(PDB ID 7GCH) (b) A depiction of the enzyme emphasizing its surface (PDB ID 7GCH) (b) A depiction of the enzyme emphasizing its surface
Temperature Profile of Earth’s Atmosphere Temperature Profile of Earth’s Atmosphere
Surface winds travel at an angle across isobars, toward low pressure. Surface winds travel at an angle across isobars, toward low pressure.
Red rocks due to oxidation of iron near the surface Red rocks due to oxidation of iron near the surface
The xy plane is painted with a uniform surface charge density which is equal to 40 nC/m2 . ... The xy plane is painted with a uniform surface charge density which is equal to 40 nC/m2 . ...
Video: Kinetic parameters & Kinetic experiment

For a complete list of videos, visit our video library