When we talk about radioactive decay, we often talk about a half-life, i.e. the amount of time it takes for the activity (particles detected per second) to decay by half. We write that as: A(t) = Ao2¬t/t1/2 (1) where Ao is the count rate at t = 0 and t/2 is the half-life. Suppose that Ao is 28 counts/second and t1/2 is 53 seconds. What is the activity at t = 106 seconds? It's often easier to do calculations with powers of e rather than powers of 2. Consequently, people will often write the activity as A(t) = Aoe-t where A is some constant whose value you have to work out. Write A in terms of the half-life. Hint: 2 = eln 2 . Suppose we plotted In A on the vertical axis and t on the horizontal axis. What would the slope be? What would the intercept be?

icon
Related questions
Question

Question

When we talk about radioactive decay, we often talk about a half-life, i.e. the amount
of time it takes for the activity (particles detected per second) to decay by half. We write
that as:
A(t) = A02-t/t1/2
(1)
where Ao is the count rate at t = 0 and t1/2 is the half-life.
Suppose that Ao is 28 counts/second and t1/2 is 53 seconds. What is the
activity at t = 106 seconds?
It's often easier to do calculations with powers of e rather than powers of 2.
Consequently, people will often write the activity as A(t) = Aoe-t where A is some constant
whose value you have to work out. Write A in terms of the half-life. Hint: 2 = eln 2.
Suppose we plotted In A on the vertical axis and t on the horizontal axis.
What would the slope be? What would the intercept be?
Now we get a fresh radioactive source and move the detect farther away, so
we get 1/4 as many counts per second. Does the slope of our graph increase, decrease, or
stay the same? Does the intercept increase, decrease, or stay the same?
Transcribed Image Text:When we talk about radioactive decay, we often talk about a half-life, i.e. the amount of time it takes for the activity (particles detected per second) to decay by half. We write that as: A(t) = A02-t/t1/2 (1) where Ao is the count rate at t = 0 and t1/2 is the half-life. Suppose that Ao is 28 counts/second and t1/2 is 53 seconds. What is the activity at t = 106 seconds? It's often easier to do calculations with powers of e rather than powers of 2. Consequently, people will often write the activity as A(t) = Aoe-t where A is some constant whose value you have to work out. Write A in terms of the half-life. Hint: 2 = eln 2. Suppose we plotted In A on the vertical axis and t on the horizontal axis. What would the slope be? What would the intercept be? Now we get a fresh radioactive source and move the detect farther away, so we get 1/4 as many counts per second. Does the slope of our graph increase, decrease, or stay the same? Does the intercept increase, decrease, or stay the same?
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 2 images

Blurred answer