« previous next »

Author Question: If 700 Joules of heat is added to a system, while the system does 550 Joules, by how much does the ... (Read 82 times)

daltonest1984

  • Hero Member
  • *****
  • Posts: 536
on: Jul 28, 2018
If 700 Joules of heat is added to a system, while the system does 550 Joules, by how much does the internal energy increase?
 a. 1250 J
  b. 150 J
  c. 700 J
  d. 150 J
  e. 1250 J

Question 2

The theory of nuclear astrophysics is that all the heavy elements like uranium are formed in the interior of massive stars. These stars eventually explode, releasing these elements into space. If we assume that at the time of the explosion there were equal amount of U-235 and U-238, how long ago did the star(s) explode that released the elements that formed our Earth? The present U-235/U-238 ratio is 0.0070 . The half-lives of U-235 and U-238 are 0.7  109 yr and 4.47  109 yr.


Ksh22

  • Sr. Member
  • ****
  • Posts: 297
Reply #1 on: Jul 28, 2018
Answer to Question 1

d

Answer to Question 2

5.9 billion years


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question

daltonest1984

  • Hero Member
  • *****
  • Posts: 536
Reply #2 on: Jul 28, 2018
Both answers were spot on, thank you once again


Ksh22

  • Sr. Member
  • ****
  • Posts: 297
Reply #3 on: Jul 28, 2018
Great! Please up vote :D


« previous next »
 

Did you know?

In the United States, there is a birth every 8 seconds, according to the U.S. Census Bureau's Population Clock.

Did you know?

The eye muscles are the most active muscles in the whole body. The external muscles that move the eyes are the strongest muscles in the human body for the job they have to do. They are 100 times more powerful than they need to be.

Did you know?

The oldest recorded age was 122. Madame Jeanne Calment was born in France in 1875 and died in 1997. She was a vegetarian and loved olive oil, port wine, and chocolate.

Did you know?

Recent studies have shown that the number of medication errors increases in relation to the number of orders that are verified per pharmacist, per work shift.

Did you know?

The Centers for Disease Control and Prevention has released reports detailing the deaths of infants (younger than 1 year of age) who died after being given cold and cough medications. This underscores the importance of educating parents that children younger than 2 years of age should never be given over-the-counter cold and cough medications without consulting their physicians.

Conduction system of the heart. Conduction system of the heart.
Pathways of the Auditory System Pathways of the Auditory System
Common Pathological Conditions of the Integumentary System Common Pathological Conditions of the Integumentary System
Latent Heat Latent Heat
United States Health Care System: Combining Business, Health, and Delivery United States Health Care System: Combining Business, Health, and Delivery
Pathway by which the nervous system controls skeletal muscle contraction Pathway by which the nervous system controls skeletal muscle contraction
Video: Pressure volume relationships - Normal inspiration and expiration

For a complete list of videos, visit our video library