« 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 104 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?

As the western states of America were settled, pioneers often had to drink rancid water from ponds and other sources. This often resulted in chronic diarrhea, causing many cases of dehydration and death that could have been avoided if clean water had been available.

Did you know?

Acetaminophen (Tylenol) in overdose can seriously damage the liver. It should never be taken by people who use alcohol heavily; it can result in severe liver damage and even a condition requiring a liver transplant.

Did you know?

Serum cholesterol testing in adults is recommended every 1 to 5 years. People with diabetes and a family history of high cholesterol should be tested even more frequently.

Did you know?

Women are 50% to 75% more likely than men to experience an adverse drug reaction.

Did you know?

In 1886, William Bates reported on the discovery of a substance produced by the adrenal gland that turned out to be epinephrine (adrenaline). In 1904, this drug was first artificially synthesized by Friedrich Stolz.

A classification system for living and extinct organisms. A classification system for living and extinct organisms.
Conduction System of the Heart Conduction System of the Heart
Inflammation. Inflammation is characterized by the presence of swelling, redness, heat, and pain. Sw Inflammation. Inflammation is characterized by the presence of swelling, redness, heat, and pain. Sw
Ears, nose, and throat (ENT) system. Ears, nose, and throat (ENT) system.
Male Reproductive System Male Reproductive System
Female Reproductive System Female Reproductive System
Video: How does asthma work?And How do you treat asthma?

For a complete list of videos, visit our video library