(AP Physics) Problem 7: Pulling a block

Having problems with the 2-dimensional FBD homework?

Check out this video of my explanation to problem 7 for guidance. 

Physics Sequence

Here's the link to the physics sequence through November.

Solutions to 5+6

Here are my solutions to problems 5 and 6 from the HW due 9/24(2A) and 9/25(1B).

Keep in mind that there might be some rounding differences in Problem 5. Considering the accuracy of each force measurement, we would argue that the sum of forces in the X and the sum of the forces in the Y is 0. So the object would move at constant velocity.

Email Address Form

Click on this link and fill out your email information.

System Schema and FBD Practice Problems (1-5)

Try the practice problems (1-5) we started in class (9/21 and 9/22) and then check your answers to these solutions.

Problem 2

Problem 2

Problem 3

Problem 4

Problem 5 (Can you spot the two mistakes on this board?)

Proportional Reasoning Examples

For the college-prep and honors classes:

Here is a video of the solutions to #3 and #10 from the proportional reasoning worksheets. Comment below this post if you have questions about a particular step. 

Bike Cop and the thief (#3) + Homework

Here's the video of my solution to question 3 involving the angle of attack of the bike cop to collide with the thief.

For homework (2A and 1B): Watch this 10-minute introductory video on forces and take notes.

Solutions to the multiple representations practice

Here are your solutions that you drew up in class (1B). There will almost certainly be one question on the AP Exam asking you to convert motion from one representation to another.

1

2

3

4

5

7

Where are 6 and 8, team?

Practice 2: Comparing Position-Time Graphs

Here are the solutions you worked out in class (2A).

3A + B

4A + B

5A

5B

Understanding Retakes

I received an email from a student yesterday inquiring about re-assessments. I thought to post my response here. I want you all to understand how you're being graded. 

If I did well on some of the standards in a quiz, but not all, would I be tested again only on the standards I did not do well on?

Once you score a 3 on a particular standard, you are set with that standard for the mastery component of your grade (80%). When the standard comes back up on future standard assessments I will still score it, but you won’t be pulled down from a 3 to a 2. Only the standards that you haven’t yet mastered can impact your grade. So you should devote the majority of the SA time to these standards. 

 Also, what constitutes proof of practice? 

Proof of practice will be the assigned homework or in the case of our first unit on scientific tools, the summer work. The summer work includes standards 3, 4, 5, 6. If you would like to practice standard 1 I have a problem on my website you can try (click files, AP Physics, 1- Scientific Thinking). You will show me the practice you completed to prepare for the next standard assessment. After a conversation with me about this practice, I will give you another SA. 

A related question: When is a convenient time for me to retake the quiz that we took two classes ago?

I plan on giving you all an SA next class on STT.1, 2, and 3 and then another one on Thursday covering 4, 5, and 6. If you would like to complete another assessment outside of these times, you can do so during your lunch period. Just let me know in advance so I can have everything prepared.

You can comment below if you have any other questions about my flavor of SBG and I will respond. 

Help with curve fitting

Watch this video if you are struggling with curve fitting. I cover data set 2 on the graphing practice worksheet. This skill is standard 4 in the scientific thinking and tools unit for college and honors classes (standard 2 for AP). Happy plotting! 

Summer Work

Use this answer key to the summer work to determine your weaknesses. Your standards assessment is on Tuesday (A) and Wednesday (B). If you are not getting some of these answers on the summer work, talk to each other or talk to me. I am available on Thursday and Friday after school. You might find the standards sheet a helpful guide. For instance, can you confidently say that you are able to "manipulate an expression to solve for any given variable (STT.3)? If not, practice!