a Using this formula show your work how old is a rock if A

a. Using this formula (show your work), how old is a rock if A = 0 and K > 0?

b. Given the ratio of a sample rock A/K = 0.212, how old is the rock? (Use scientific notation for your answer but round the decimal portion to three decimal places, same as equation and show your work).

Solution

t=1.260*10⁹(ln (1 + 8.33(A/K))/ln2)

at A=0

t= 1.260*10⁹(ln 1/ln2)= 1.260*10⁹*0=0 yrs

b. A/K=0.212

t= 1.260*10⁹(ln (1+8.33*.212)/ln2)

t=1.260*10⁹(ln 2.76596/ln2)= 1.849*10⁹ yrs