Radioactivity

After 548 hours decreases the activity of a radioactive substance to 1/9 of the initial value. What is the half-life of the substance?

Result

t1/2 =  172.9 hours

Solution:

Solution in text t__1/2 =







Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):

Showing 0 comments:
1st comment
Be the first to comment!
avatar




To solve this example are needed these knowledge from mathematics:

Next similar examples:

  1. Sequence
    seq Calculate what member of the sequence specified by ? has value 86.
  2. Computer revolution
    Intel386 When we started playing with computers, the first processor, which I remember was the Intel 8080 from 1974, with the performance of 0.5 MIPS. Calculate how much percent a year rose CPU performance when Intel 486DX from 1992 has 54 MIPS. What
  3. Demographics
    population The population grew in the city in 10 years from 42000 to 54500. What is the average annual percentage increase of population?
  4. Intercept with axis
    log_10 F(x)=log(x+4)-2, what is the x intercept
  5. Half life
    Bi Determine the half life of bismuth, when bismuth weight from the original weight of 32 g was only 2 grams in 242 minutes.
  6. Crystal
    crystal Crystal grows every month 2.2 promile of its mass. For how many months to grow a crystal from weight 160 g to 311 g?
  7. Compound interest
    exponential_usd Calculate time when deposit in the bank with interest 2.5% p.a. doubles.
  8. Population
    population_1 The town has 65,000 inhabitants. 40 years ago there were 157,000. How many people will live in town in 10 years if the average rate in population is as in previous years?
  9. When will I be a millionaire?
    milionar_kedy Shawn monthly send 220 euros to the bank, which he deposits bear interest of 2.4% p.a. Calculate how many months must Shawn save to save 1000000 euros? Inflation, interest rate changes or bank failures ignore.
  10. Geometric sequence 3
    sequence In geometric sequence is a8 = 312500; a11= 39062500; sn=1953124. Calculate the first item a1, quotient q and n - number of members by their sum s_n.
  11. Exp
    old_calculator If ?, then n is:
  12. Sum-log
    complex_log The sum of two numbers is 32, the sum of their logarithms (base 10) is 2.2. Determine these numbers.
  13. Exponential equation
    exp In the set R solve the equation: ?
  14. Logarithmic equation
    nat_log_ln Solve equation: log33(3x + 21) = 0
  15. Dice
    dices How many times must throw the dice, the probability of throwing at least one six was greater than 90%?
  16. Future of libraries
    library You know that thanks to the Internet, electronic communications and developing online resources on the Internet annually declining number of traditional readership by 17%. These deal is irreversible evolutionary shift from old books from libraries to immed
  17. Seating rules
    school_class In a class are 24 seats but in 7.B class are only 18 students. How many ways can student seat? (The class has 12 benches. A bench is for a pair of students.) Result (large number) logarithm and thus write down as powers of 10.