Call Now to Set Up Tutoring:

(888) 888-0446

AP Physics 2 : AP Physics 2

Study concepts, example questions & explanations for AP Physics 2

Create An Account

All AP Physics 2 Resources

6 Diagnostic Tests 149 Practice Tests Question of the Day Flashcards Learn by Concept

Example Questions

Example Question #31 : Radioactive Nuclear Decay

A sample is taken of a radioactive element. It has an activity of 1991 Bq . Two hours later, it has an activity of 28 Bq .

Determine the activity 30 minutes after the initial reading.

Possible Answers:

822Bq

None of these

686Bq

711Bq

305Bq

Correct answer:

686Bq

Explanation:

Determination of decay constant:

$A=A_0e^{-\lambda t}$

Solving for $\lambda$

$-ln(\frac{A}{A_0})*\frac{1}{t}=\lambda$

Converting hours to minutes and plugging in values:

$-ln(\frac{28}{1991})*\frac{1}{120}=\lambda$

$\frac{.0355}{min}=\lambda$

Again using

$A=A_0e^{-\lambda t}$

$A=1991e^{-.0355*30}$

A=686Bq

Report an Error

Example Question #31 : Radioactive Nuclear Decay

A sample is taken of a radioactive element. It has an activity of 1991 Bq . Two hours later, it has an activity of 28 Bq .

Determine the number of radioactive atoms in the initial sample.

Possible Answers:

$3.36*10^{6}atoms$

196000atoms

88000atoms

75000atoms

None of these

Correct answer:

$3.36*10^{6}atoms$

Explanation:

Determination of decay constant:

$A=A_0e^{-\lambda t}$

Solving for $\lambda$

$-ln(\frac{A}{A_0})*\frac{1}{t}=\lambda$

Converting hours to seconds and plugging in values:

$-ln(\frac{28}{1991})*\frac{1}{7200}=\lambda$

$\frac{5.92*10^{-4}}{s}=\lambda$

Using $A=\lambda N$

Plugging in values:

$1991=5.92*10^{-4} N$

$N=3.36*10^{6}atoms$

Report an Error

Example Question #41 : Radioactive Nuclear Decay

Vt physics 11 20 15 radioactivity

The given diagram shows the change in mass of an unstable radioactive isotope over time. Based on this diagram, what is the half-life of the isotope?

Possible Answers:

$3\textup{ hr}$

$2\textup{ hr}$

$4\textup{ hr}$

$1\textup{ hr}$

There is not enough information in the diagram to answer this question.

Correct answer:

$1\textup{ hr}$

Explanation:

In this question, we're presented with a diagram that shows us the change in mass of an isotope as a function of time.

To find the half-life, we first need to find the point on the y-axis where the mass is half of its starting value. Since $40\: grams$ of the isotope is present initially, we'll have to direct our attention to the point on the y-axis that shows $20\: grams$ of the isotope.

Next, we'll need to see where this value on the y-axis matches up with the corresponding value on the x-axis. From the graph, we can see that the $20\: grams$ point of the y-axis matches up approximately with the $1\: hour$ mark on the x-axis. Thus, we can conclude that the time it takes for half of the isotope to decay is equal to $1\: hour$ , which equates to a half-life of $1\: hour$ .

Report an Error

Example Question #71 : Quantum And Nuclear Physics

Which of the following graphs best represents the decay of a radioactive isotope over time?

Possible Answers:

Vt physics 11 22 15 incorrect answer 2

Vt physics 11 22 15 incorrect answer 1

Vt physics 11 22 15 incorrect answer 3

None of these.

Vt physics 11 22 15 correct answer

Correct answer:

Vt physics 11 22 15 correct answer

Explanation:

For this question, we need to determine which graph correctly represents the decay of a radioactive isotope over time. First, recall that all radioactive decay processes are first-order reactions. Thus, they take the general form:

Rate=k[isotope]

Where represents the rate constant for the reaction. Thus, at any given time during the decay of the unstable isotope, the rate is dependent on the concentration of the isotope present. Therefore, as the decay proceeds, there will be less and less of the isotope present as time goes on. This, in turn, means that the rate will also drop proportionately as the concentration of isotope goes down. This would result in a graph in which the decay process begins rapidly, but then begins to decline and level off as time goes on.

Another way of looking at this is to note that on a graph of isotope concentration vs. time, the slope of the line tangent to any point on the graph represents the rate of decay at that point. Thus, the correct graph will have a steep slope initially, but as time goes on (as the value of x on the graph becomes larger), the slope will decrease until it levels off.

Report an Error

Example Question #72 : Quantum And Nuclear Physics

What is the equation for the alpha decay of radium-226?

Possible Answers:

$_{88}^{226}Ra\rightarrow _{1}^{0}e +_{87}^{226}Fr$

$_{88}^{226}Ra+_{2}^{4}He\rightarrow_{86}^{222}Rn$

$_{88}^{226}Ra\rightarrow4 _{1}^{1}H+_{86}^{222}Rn$

$_{88}^{226}Ra\rightarrow _{2}^{4}He+_{86}^{222}Rn$

$_{88}^{226}Ra\rightarrow _{-1}^{\ 0}e+_{89}^{226}Ac$

Correct answer:

$_{88}^{226}Ra\rightarrow _{2}^{4}He+_{86}^{222}Rn$

Explanation:

If radium experiences alpha decay, it will lose four total nucleons and two protons. Thus, the mass number will decrease by 4 and the atomic number will decrease by 2.

$_{88}^{226}Ra\rightarrow _{2}^{4}He+_{86}^{222}Rn$

Report an Error

Example Question #42 : Radioactive Nuclear Decay

Neptunium-235 has a half-life of 400 days . Determine the radioactive decay constant.

Possible Answers:

$\frac{7.77*10^{-3}}{day}$

$\frac{5.91*10^{-3}}{day}$

$\frac{8.24*10^{-3}}{day}$

$\frac{1.73*10^{-3}}{day}$

None of these

Correct answer:

$\frac{1.73*10^{-3}}{day}$

Explanation:

Using

$t_{1/2}=\frac{ln(2)}{\lambda}$

Solving for $\lambda$

$\lambda=\frac{ln(2)}{t_{1/2}}$

Plugging in values:

$\lambda=\frac{.693}{400days}$

$\lambda=\frac{1.73*10^{-3}}{day}$

Report an Error

Example Question #43 : Radioactive Nuclear Decay

A scientist takes a sample of a newly discovered radioactive isotope, which has an activity of $1989 \textup{ Bq}$ . $8 \textup{ s}$ later, it has an activity of $10 \textup{ Bq}$ .

Determine the nuclear decay constant.

Possible Answers:

$\frac{0.114}{\textup{s}}$

$\frac{0.896}{\textup{s}}$

None of these

$\frac{0.662}{\textup{hr}}$

$\frac{0.662}{\textup{s}}$

Correct answer:

$\frac{0.662}{\textup{s}}$

Explanation:

Use the equation for radioactive decay:

$A=A_0e^{-\lambda t}$

Solving for $\lambda$ :

$\lambda=-\frac{1}{t}ln(\frac{A}{A_0})$

Plugging in values:

$\lambda=-\frac{1}{8}ln(\frac{10}{1989})$

$\lambda=\frac{.662}{\textup{s}}$

Report an Error

Example Question #56 : Atomic And Nuclear Physics

A scientist takes a sample of a newly discovered radioactive isotope, which has an activity of $1989 \textup{ Bq}$ . $8 \textup{ s}$ later, it has an activity of $10 \textup{ Bq}$ .

Determine the half-life.

Possible Answers:

$1.05\textup{ s}$

$1.69\textup{ s}$

$64\textup{ s}$

None of these

$.85\textup{ s}$

Correct answer:

$1.05\textup{ s}$

Explanation:

Use the equation for radioactive decay:

$A=A_0e^{-\lambda t}$

Solving for $\lambda$ :

$\lambda=-\frac{1}{t}ln(\frac{A}{A_0})$

Plugging in values:

$\lambda=-\frac{1}{8}ln(\frac{10}{1989})$

$\lambda=\frac{.662}{second}$

Use the following relationship:

$t_{\frac{1}{2}}=\frac{ln(2)}{\lambda}$

Plugging in values:

$t_{\frac{1}{2}}=\frac{.693}{.662}$

$t_{\frac{1}{2}}=1.05\textup{ s}$

Report an Error

Example Question #47 : Radioactive Nuclear Decay

A scientist takes a sample of a newly discovered radioactive isotope, which has an activity of $1989 \textup{ Bq}$ . $8 \textup{ s}$ later, it has an activity of $10 \textup{ Bq}$ .

Determine the activity $3 \textup{ s}$ after the initial reading.

Possible Answers:

None of these

$611\textup{ Bq}$

$273 \textup{ Bq}$

$844\textup{ Bq}$

$199\textup{ Bq}$

Correct answer:

$273 \textup{ Bq}$

Explanation:

Use the equation for radioactive decay:

$A=A_0e^{-\lambda t}$

Solving for $\lambda$ :

$\lambda=-\frac{1}{t}ln(\frac{A}{A_0})$

Plugging in values:

$\lambda=-\frac{1}{8}ln(\frac{10}{1989})$

$\lambda=\frac{.662}{second}$

Again using the first equation:

$A=A_0e^{-\lambda t}$

Plugging in values:

$A=1989*e^{-.662* 3}$

$A=273\textup{ Bq}$

Report an Error

Example Question #51 : Atomic And Nuclear Physics

Determine the number of radioactive nuclei $4 \textup{ s}$ after the initial reading.

Possible Answers:

$184\textup{ nuclei}$

None of these

$212\textup{ nuclei}$

$449\textup{ nuclei}$

$260\textup{ nuclei}$

Correct answer:

$212\textup{ nuclei}$

Explanation:

Use the equation for radioactive decay:

$A=A_0e^{-\lambda t}$

Solving for $\lambda$ :

$\lambda=-\frac{1}{t}ln(\frac{A}{A_0})$

Plugging in values:

$\lambda=-\frac{1}{8}ln(\frac{10}{1989})$

$\lambda=\frac{.662}{second}$

Use the following two relationships:

$A=A_0e^{-\lambda t}$

and

$A=\lambda N$

Combining equations:

$\lambda N=A_0e^{-\lambda t}$

Solving for :

$N=\frac{A_0e^{-\lambda t}}{\lambda}$

Plugging in values:

$N=\frac{1984*e^{-.662*4}}{.662}$

$N=212\textup{ nuclei}$

Report an Error

View Tutors

Fatima
Certified Tutor

Virginia Commonwealth University, Bachelor, Biomedical Engineering.

View Tutors

Mikhail
Certified Tutor

Tbilisi State University Georgia, Bachelor of Science, Chemistry. Tbilisi State University, Doctor of Science, Organic Chemis...

View Tutors

Laura
Certified Tutor

California State University-Fullerton, Bachelor in Business Administration, Business Administration and Management.

All AP Physics 2 Resources

6 Diagnostic Tests 149 Practice Tests Question of the Day Flashcards Learn by Concept

Popular Subjects

Chemistry Tutors in Los Angeles, LSAT Tutors in Atlanta, Calculus Tutors in San Francisco-Bay Area, Biology Tutors in Houston, Algebra Tutors in Houston, LSAT Tutors in Chicago, Biology Tutors in San Francisco-Bay Area, MCAT Tutors in Houston, Physics Tutors in Boston, Spanish Tutors in Atlanta

Popular Courses & Classes

MCAT Courses & Classes in Atlanta, GRE Courses & Classes in Philadelphia, GMAT Courses & Classes in San Diego, MCAT Courses & Classes in Chicago, MCAT Courses & Classes in Dallas Fort Worth, ISEE Courses & Classes in Houston, MCAT Courses & Classes in Los Angeles, Spanish Courses & Classes in Los Angeles, ISEE Courses & Classes in Denver, MCAT Courses & Classes in Boston

Popular Test Prep

LSAT Test Prep in Atlanta, ISEE Test Prep in Houston, LSAT Test Prep in San Francisco-Bay Area, SAT Test Prep in Atlanta, LSAT Test Prep in New York City, LSAT Test Prep in San Diego, SSAT Test Prep in Chicago, SSAT Test Prep in Seattle, GMAT Test Prep in Seattle, GRE Test Prep in Dallas Fort Worth

DMCA Complaint

If you believe that content available by means of the Website (as defined in our Terms of Service) infringes one or more of your copyrights, please notify us by providing a written notice (“Infringement Notice”) containing the information described below to the designated agent listed below. If Varsity Tutors takes action in response to an Infringement Notice, it will make a good faith attempt to contact the party that made such content available by means of the most recent email address, if any, provided by such party to Varsity Tutors.

Your Infringement Notice may be forwarded to the party that made the content available or to third parties such as ChillingEffects.org.

Please be advised that you will be liable for damages (including costs and attorneys’ fees) if you materially misrepresent that a product or activity is infringing your copyrights. Thus, if you are not sure content located on or linked-to by the Website infringes your copyright, you should consider first contacting an attorney.

Please follow these steps to file a notice:

You must include the following:

A physical or electronic signature of the copyright owner or a person authorized to act on their behalf; An identification of the copyright claimed to have been infringed; A description of the nature and exact location of the content that you claim to infringe your copyright, in \ sufficient detail to permit Varsity Tutors to find and positively identify that content; for example we require a link to the specific question (not just the name of the question) that contains the content and a description of which specific portion of the question – an image, a link, the text, etc – your complaint refers to; Your name, address, telephone number and email address; and A statement by you: (a) that you believe in good faith that the use of the content that you claim to infringe your copyright is not authorized by law, or by the copyright owner or such owner’s agent; (b) that all of the information contained in your Infringement Notice is accurate, and (c) under penalty of perjury, that you are either the copyright owner or a person authorized to act on their behalf.

Send your complaint to our designated agent at:

Charles Cohn Varsity Tutors LLC
101 S. Hanley Rd, Suite 300
St. Louis, MO 63105

Or fill out the form below:

Do not fill in this field

Contact Information

* Full legal name

Company name

* Phone number

* Email address

Address

* Address1

Address2

* City

* State

* Zipcode

* Country

Complaint Details

* URL of copyrighted work (where your original material is located)

* Please describe the copyrighted work so that it may be easily identified

I am the owner, or an agent authorized to act on behalf of the owner of an exclusive right that is allegedly infringed.

I have a good faith belief that the use of the material in the manner complained of is not authorized by the copyright owner, its agent, or the law.

This notification is accurate.

I acknowledge that there may be adverse legal consequences for making false or bad faith allegations of copyright infringement by using this process.

* Signature (your digital signature is legally binding)

HIGH SCHOOL

GRADUATE SCHOOL

K-8

Search 50+ Tests

math tutoring

science tutoring

foreign languages

elementary tutoring

other

Search 350+ Subjects

AP Physics 2 : AP Physics 2

Study concepts, example questions & explanations for AP Physics 2

All AP Physics 2 Resources

Example Questions

Example Question #31 : Radioactive Nuclear Decay

Example Question #31 : Radioactive Nuclear Decay

Example Question #41 : Radioactive Nuclear Decay

Example Question #71 : Quantum And Nuclear Physics

Example Question #72 : Quantum And Nuclear Physics

Example Question #42 : Radioactive Nuclear Decay

Example Question #43 : Radioactive Nuclear Decay

Example Question #56 : Atomic And Nuclear Physics

Example Question #47 : Radioactive Nuclear Decay

Example Question #51 : Atomic And Nuclear Physics

All AP Physics 2 Resources

Report an issue with this question

DMCA Complaint

Contact Information

Address

Complaint Details

Email address:
Your name:
Feedback: