Transcript Half-Life and Doubling Time - North Carolina School of

Half-Life and Doubling Time
Half-Life
• Phenomenon is modeled by a decreasing
exponential function (shows decay).
• Half-life is the amount of time (length of the
x-interval) over which the value of the
phenomenon is cut in half.
Doubling Time
• Phenomenon is modeled by an increasing
exponential function
• Doubling time is the amount of time (length
of the x-interval) over which the
phenomenon doubles in size.
Carbon 14
Carbon 14 has a half-life of 5730
years.
Time (in years)
Amt of Carbon 14
0
1.00
`
The world population doubles
every 51.8 years. At the
beginning of the twentieth
century, the world population was
1.6 billion. What was the
population at the end of the
twentieth century?
The world population doubles every 51.8 years. At
the beginning of the twentieth century, the world
population was 1.6 billion. What was the population
at the end of the twentieth century?
Time (in years)
Population
0
1.6 billion
Fran Data
Date
Sept. 6
Sept. 7
Sept. 8
Sept. 9
Sept. 10
Sept. 11
Sept. 12
Sept. 13
Customers without Power
1,159,000
804,000
515,000
340,500
195,200
136,300
77,000
37,600