« 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 101 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?

Nearly all drugs pass into human breast milk. How often a drug is taken influences the amount of drug that will pass into the milk. Medications taken 30 to 60 minutes before breastfeeding are likely to be at peak blood levels when the baby is nursing.

Did you know?

Multiple sclerosis is a condition wherein the body's nervous system is weakened by an autoimmune reaction that attacks the myelin sheaths of neurons.

Did you know?

About 3.2 billion people, nearly half the world population, are at risk for malaria. In 2015, there are about 214 million malaria cases and an estimated 438,000 malaria deaths.

Did you know?

Medication errors are three times higher among children and infants than with adults.

Did you know?

Aspirin may benefit 11 different cancers, including those of the colon, pancreas, lungs, prostate, breasts, and leukemia.

Parts of the Hand Used in Palpation; Dorsal Surface Parts of the Hand Used in Palpation; Dorsal Surface
Factors Affecting Body Temperature Factors Affecting Body Temperature
The level in the coolant recovery system raises and lowers with engine temperature. The level in the coolant recovery system raises and lowers with engine temperature.
A thin laser beam traveling in air strikes the surface of a glass plate at 41.2° with the ... A thin laser beam traveling in air strikes the surface of a glass plate at 41.2° with the ...
The temperature of an average lightning bolt is 3.0 x 104 °C. What is the equiva The temperature of an average lightning bolt is 3.0 x 104 °C. What is the equiva
One surface barrier to infection One surface barrier to infection
Video: Magnetic resonance imaging (MRI)

For a complete list of videos, visit our video library