Posted by **hannah** on Tuesday, November 12, 2013 at 6:52pm.

1.The remains of an old campﬁre are unearthed and it is found that there is only 80% as much radioactive carbon-14 in the charcoal samples from the campﬁre as there is in modern living trees. If the half-life of carbon- 14 is 5730 years, how long ago did the campﬁre burn?

- math -
**Kuai**, Wednesday, November 13, 2013 at 12:36am
Po = Poe^kt

1/2 = e^5730k

Ln(1/2) = Lne^5730k

Ln(1/2) = 5730k

K = ln(1/2)/5730

Poe^ln(1/2)/5730 *t

.80P0 = Poe^ln(1/2)/5730 *t

.8 = e^ln(1/5)/5730 t

ln(.8) = ln(.5)/5730t lne

ln(.8) = ln(.5)/ 5730 t

t = 5730ln(.8)/ln(.5)

- math -
**Chris **, Tuesday, March 10, 2015 at 11:44pm
t=1844.65 years

- math -
**ساره**, Thursday, March 24, 2016 at 8:28am
found in an Egyptian pyramid contains 75% of its original carbon_14 which has about 5730 years as half-life.

## Answer This Question

## Related Questions

- physics - A cylindrical ﬁshing reel has a mass of 0.899 kg and a radius ...
- MATH - A track meet awards 6, 5, 4, 3, 2 and 1 points for 1st, 2nd, 3rd, 4th, ...
- Chemistry - A sample of charcoal is found to have only 1/8th of Carbon-14. Half-...
- Physics - A mountain-climbing expedition establishes two intermediate camps, ...
- Physics 1 - A mountain-climbing expedition establishes two intermediate camps, ...
- Calculus - ﬁnd the ﬁrst three non-zero terms of the Maclaurin ...
- math - Fewer than 107 girls attend a basketball camp. A total of 180 children ...
- Physics - Note: Take East as the positive direction. A(n) 86 kg ﬁsherman...
- physics - The electrons in a beam are moving at 2.8 × 108 m/s in an electric &#...
- physics - A 2.31 × 103 kg car requires 4.2 kJ of work to move from rest to some...

More Related Questions