All AP Physics 2 Resources
Example Questions
Example Question #19 : Radioactive Nuclear Decay
A test is done on a sample of a newly discovered radioactive nuclei, which has an activity of . later, it has an activity of .
Determine the activity after the initial reading.
None of these
Using the relationship:
Here, is the activity at a given time, is the intial activity, is the radioactive decay constant, and is the time passed since the initial reading.
Rearranging the equation to solve for .
Converting minutes to seconds and plugging in values.
Again using the relationship
Using the new , which is equal to
Example Question #20 : Radioactive Nuclear Decay
A scientist takes a sample of a newly discovered radioactive element, which has an activity of . 10 minutes later, it has an activity of .
Determine the number of radioactive nuclei in the original sample.
None of these
Use the relationship:
Where is the activity at a given time, is the initial activity, is the radioactive decay constant and is the time passed since the initial reading.
Rearrange to solve for .
Convert minutes to seconds and plug in values.
It is then necessary to use the relationship:
Use the initial activity and the calculated decay constant:
Example Question #381 : Ap Physics 2
A scientist is working with a new radioactive nuclei. A sample has an activity of . 8 minutes later, it has an activity of .
Determine the nuclear decay constant.
None of these
Use the relationship:
Here, is the activity at a given time, is the initial activity, is the radioactive decay constant, and is the time passed since the initial reading.
Rearrange the equation to solve for .
Convert minutes to seconds and plug in values.
Example Question #381 : Ap Physics 2
A scientist is working with a new radioactive nuclei. A sample has an activity of . 8 minutes later, it has an activity of .
Determine the activity 4 minutes after the initial reading.
None of these
Use the relationship:
Here, is the activity at a given time, is the initial activity, is the radioactive decay constant, and is the time passed since the initial reading.
Rearranging the equation to solve for .
Convert minutes to seconds and plug in values.
Again, use the relationship:
Using the new , which is equal to
Example Question #381 : Ap Physics 2
A scientist is working with a new radioactive nuclei. A sample has an activity of . 8 minutes later, it has an activity of .
Determine the number of radioactive atoms at the time of the initial reading.
None of these
Use the relationship:
Here, is the activity at a given time, is the initial activity, is the radioactive decay constant, and is the time passed since the initial reading.
Rearrange the equation to solve for .
Convert minutes to seconds and plug in values.
It is then necessary to use the relationship:
Use the initial activity and the calculated decay constant:
Example Question #34 : Atomic And Nuclear Physics
A scientist runs a test on a radioactive sample and finds that it has an activity of . Three days later, she runs another test and finds the activity to be .
Another sample is tested. It has an activity of . Determine the number of radioactive nuclei in it.
None of these
Use the relationship:
Where is the activity at a given time, is the initial activity, is the radioactive decay constant and is the time passed since the initial reading.
Rearrange to solve for .
Convert days to seconds and plug in values.
It is then necessary to use the relationship:
Use the initial activity and the calculated decay constant:
Example Question #382 : Ap Physics 2
A scientist runs a test on a radioactive sample and finds that it has an activity of . Three days later, she runs another test and finds the activity to be .
Determine the number of radioactive nuclei in the original sample.
None of these
Use the relationship:
Where is the activity at a given time, is the initial activity, is the radioactive decay constant and is the time passed since the initial reading.
Rearrange to solve for .
Convert days to seconds and plug in values.
It is then necessary to use the relationship:
Use the initial activity and the calculated decay constant:
Example Question #381 : Ap Physics 2
A scientist runs a test on a radioactive sample and finds that it has an activity of . Three days later, she runs another test and finds the activity to be .
Determine the half-life.
None of these
Use the relationship:
Where is the activity at a given time, is the initial activity, is the radioactive decay constant and is the time passed since the initial reading.
Rearrange to solve for .
Convert days to seconds and plug in values.
Use the relationship:
Plugin the calculated value for :
Example Question #51 : Quantum And Nuclear Physics
A scientist is working with a new radioactive nuclei. A sample has an activity of . 8 minutes later, it has an activity of .
Determine the half life.
None of these
Use the relationship:
Here, is the activity at a given time, is the initial activity, is the radioactive decay constant, and is the time passed since the initial reading.
Rearrange the equation to solve for .
Convert minutes to seconds and plug in values.
Use the relationship:
Plug in the calculated value for
Example Question #38 : Atomic And Nuclear Physics
A scientist runs a test on a radioactive sample and finds that it has an activity of . Three days later, she runs another test and finds the activity to be .
Determine the activity of the sample 12 hours after the original reading.
None of these
Use the relationship:
Where is the activity at a given time, is the initial activity, is the radioactive decay constant and is the time passed since the initial reading.
Rearrange to solve for .
Convert days to seconds and plug in values.
Again, use the relationship:
Use the new , which is equal to