Physics Honors/AP 1 and 2

Homework

# Physics Chapter 4: 8 Force, Friction, and Inclined Planes

## Homework

Text Reading: Giancoli, Physics - Principles with Applications, 4: 8

##### Study Points
• Section 8: There are two types of friction: that which resists motion starting in an unmoving object is static friction and that that which resists the motion of a moving object is kinetic friction.
• Section 9: One can cultivate a general process for approaching any physics problem.

### Web Lecture

Read the following weblecture before chat: Friction on a flat surface

### Study Activity

Take a look at Friction on a Ramp to get a sense of what is happening when we have a block on a incline with friction present.
• Identify the graph lines with the force vectors (colors match). Note that the slope turns red when there is not enough static friction to keep the block at rest, where the magnitude of gravitational pull along the block equals the friction due to the normal force and coefficient of friction μ.
• What is the smallest angle where the block slides if μ is 0.1? if it is 0.5? if it is 1.0?
• Will the block slide if the angle is at extremes, 0° or 90°, with any value of μ

Physics at Boston University

### Chat Preparation Activities

• Forum question: The Moodle forum for the session will assign a specific study question for you to prepare for chat. You need to read this question and post your answer before chat starts for this session.
• Mastery Exercise: The Moodle Mastery exercise for the chapter will contain sections related to our chat topic. Try to complete these before the chat starts, so that you can ask questions.

### Chapter Quiz

• Required: Complete the Mastery exercise with a passing score of 85% or better.
• Go to the Moodle and take the quiz for this chat session to see how much you already know about astronomy!

### Lab Work

If you want lab credit for this course, you must complete at least 12 labs (honors course) or 18 labs (AP students). One or more lab exercises are posted for each chapter as part of the homework assignment. We will be reviewing lab work at regular intervals, so do not get behind!