Author Question: If 700 Joules of heat is added to a system, while the system does 550 Joules, by how much does the ... (Read 55 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?

People with high total cholesterol have about two times the risk for heart disease as people with ideal levels.

Did you know?

Symptoms of kidney problems include a loss of appetite, back pain (which may be sudden and intense), chills, abdominal pain, fluid retention, nausea, the urge to urinate, vomiting, and fever.

Did you know?

Illness; diuretics; laxative abuse; hot weather; exercise; sweating; caffeine; alcoholic beverages; starvation diets; inadequate carbohydrate consumption; and diets high in protein, salt, or fiber can cause people to become dehydrated.

Did you know?

The training of an anesthesiologist typically requires four years of college, 4 years of medical school, 1 year of internship, and 3 years of residency.

Did you know?

Since 1988, the CDC has reported a 99% reduction in bacterial meningitis caused by Haemophilus influenzae, due to the introduction of the vaccine against it.

For a complete list of videos, visit our video library