Author Question: If 700 Joules of heat is added to a system, while the system does 550 Joules, by how much does the ... (Read 83 times)

daltonest1984

  • Hero Member
  • *****
  • Posts: 536
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
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
Both answers were spot on, thank you once again



Ksh22

  • Sr. Member
  • ****
  • Posts: 297

 

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?

More than 150,000 Americans killed by cardiovascular disease are younger than the age of 65 years.

Did you know?

The longest a person has survived after a heart transplant is 24 years.

Did you know?

The liver is the only organ that has the ability to regenerate itself after certain types of damage. As much as 25% of the liver can be removed, and it will still regenerate back to its original shape and size. However, the liver cannot regenerate after severe damage caused by alcohol.

Did you know?

If you could remove all of your skin, it would weigh up to 5 pounds.

For a complete list of videos, visit our video library