This topic contains a solution. Click here to go to the answer

Author Question: An archaeologist finds the 14C in a sample of 3.10 g of material to be decaying at 107 counts per ... (Read 89 times)

nummyann

  • Hero Member
  • *****
  • Posts: 576
An archaeologist finds the 14C in a sample of 3.10 g of material to be decaying at 107 counts per second. A modern 1.00-g sample of the same material decays at 151 counts per second. The half-life of 14C is 5730 y. How old is the sample?
 
  A) 12,200 y
  B) 8460 y
  C) 25,100 y
  D) 12,600 y

Question 2

A porch roof that slopes upward at 45 measures 3.0 m  5.0 m. It is covered with a slab of insulating material that is 2.0 cm thick.
 
  If the density of the insulation is 15 kg/m3, what is the weight of the insulation, in pounds, on the roof? (1.00 kg weighs 2.2 lb and density is mass per unit volume.)
  A) 4.5 lb
  B) 9.0 lb
  C) 20 lb
  D) 990 lb
  E) 9.9 lb



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

cuttiesgirl16

  • Sr. Member
  • ****
  • Posts: 345
Answer to Question 1

A

Answer to Question 2

E



nummyann

  • Hero Member
  • *****
  • Posts: 576
Both answers were spot on, thank you once again




 

Did you know?

Prostaglandins were first isolated from human semen in Sweden in the 1930s. They were so named because the researcher thought that they came from the prostate gland. In fact, prostaglandins exist and are synthesized in almost every cell of the body.

Did you know?

Pregnant women usually experience a heightened sense of smell beginning late in the first trimester. Some experts call this the body's way of protecting a pregnant woman from foods that are unsafe for the fetus.

Did you know?

People who have myopia, or nearsightedness, are not able to see objects at a distance but only up close. It occurs when the cornea is either curved too steeply, the eye is too long, or both. This condition is progressive and worsens with time. More than 100 million people in the United States are nearsighted, but only 20% of those are born with the condition. Diet, eye exercise, drug therapy, and corrective lenses can all help manage nearsightedness.

Did you know?

Hip fractures are the most serious consequences of osteoporosis. The incidence of hip fractures increases with each decade among patients in their 60s to patients in their 90s for both women and men of all populations. Men and women older than 80 years of age show the highest incidence of hip fractures.

Did you know?

Children of people with alcoholism are more inclined to drink alcohol or use hard drugs. In fact, they are 400 times more likely to use hard drugs than those who do not have a family history of alcohol addiction.

For a complete list of videos, visit our video library