Quick Question: Starting on page 52 of your book, answer the following questions. 41, 46, 47, 54, and 56

Today’s Objective: I understand the difference between speed, average velocity, and instantaneous velocity.

Chapter 1: Review of math, graphs, the metric system & prefixes, etc. Things to note in book: Chapter 1: Review of math, graphs, the metric system & prefixes, etc. Read Significant Digits on page 7 and Precision Versus Accuracy on page 12 Tables starting on page 910 contain very helpful information, symbols, Si units, data that may be needed for various problems Vectors are in boldface type. Velocity are red. Displacement are green. Appendix A is a math handbook …good for review

Practice Problems on pages 39 & 41 Due tomorrow: Practice Problems on pages 39 & 41

Vocabulary Cards & Quick on Socrative.com Due now: Vocabulary Cards & Quick on Socrative.com

First Marking Period Project Due Tuesday 2/21: First Marking Period Project Dwilsonscienceandmath.weebly.com

Project Requirements: Honors level topic… research a subject that is complicated enough to be studied in an honors physics class Decide on the type of project you want to do… i.e. an experiment, demonstration, paper, power point, model, etc. Describe your choice on the back of the rubric and submit to instructor for approval ASAP Use rubric as guide while completing the project & grade yourself on it before turning it in WITH your project

Write a learning summary describing your experience with this project Write a learning summary describing your experience with this project. Discuss: Why you chose the topic…what experiences have you had or wondered about or made you find this topic interesting? Why did you chose the way your topic was presented…why did you pick a power point, or a paper, or an experiment? Was it fun or boring? Too easy or too difficult? What was the best part? The hardest part? Would you recommend it to someone else? Why? Discuss your experience like you telling a friend about it. It should be at least 2 FULL paragraphs long

Find the slope of a line that contains these points: Skill Review: Find the slope of a line that contains these points: (7,8) and (3,2)

We express our speed when driving the car in mph or miles per hour. Written mathematically, the “per” indicates a ratio and ultimately a division problem. Miles Hour

In formulas, sometimes it is helpful to think of the = as “is defined or determined by” This motion diagram shows Sharon as she travels to school. At t = .05 hrs, her speed is 0. At that instant, she is stopped. Her speedometer reads 0 mph.

Average speed is calculated by finding the slope of the line between 2 points. Choose 2 points that meet the requirements of the problem & find the slope using 2 point method. I use (0,0) whenever possible because zeroes are easy to calculate.

At t = .05 hours, Sharon had traveled 1.5 miles. At t = .18 hours, she had traveled 4 miles. Calculate her average speed. (.05, 1.5) (.18, 4) (4 – 1.5) = (.18 - .05) 2.5 .13 = 19.2 mph

Instantaneous Speed is the speed at a particular instant or point in time. Think of it as the reading on your speedometer the instant you see the police cruiser’s flashing light in your rearview mirror.

When the speed is not constant you can calculate it for a specific position by using a line tangent to the curve at that specific point. (A tangent is the line intersecting the curve at only 1 point.) Calculate the slope of the tangent and that is the instantaneous speed.

To draw a tangent line, pick a point on the graph To draw a tangent line, pick a point on the graph. Using a ruler, draw a line that touches the curve at that one point. Find the slope of the line you drew. At which point is the speed the greatest? At t = 2 At t = 4.4 At d = 35

Calculate the slope of the blue line. The slope of the position-time graph is obviously not the object’s speed since speed cannot be a negative value. Speed is the absolute value of the slope of a position-time graph

Velocity can be negative because it is a vector and includes the direction of the motion.

Negative Velocity Particle moves from + position to negative…so the position has a negative value Time has a positive value because we are graphing the position after the point where we started recording the time. Since d is (–) & t is (+), V is (-) Velocity = D d D t

Scalar Vector

Average Velocity = displacement Average velocity is the object’s rate of motion (speed) in a given time interval. Average Velocity = displacement time The black arrow at the bottom represents the skateboarder’s change in position. So displacement is represented by x in the formula.

Instantaneous Velocity is defined just like instantaneous speed but it also includes the direction of the motion. It is the velocity of the object at a particular instant. An instant is the smallest period of time possible: a second, .10 second, .001 second, 1/1,000,000 of a second, etc.

Ryan and Victor are driving to the beach. What are 3 ways they can change their velocity? Speed up. Slow down. Change direction.

Kat drives to 20 miles to the mall in 30 minutes Kat drives to 20 miles to the mall in 30 minutes. When she gets there, she realizes she left her money at home, turns around immediately, and goes home. When she got home, Henri was there so she stayed home to study physics. Calculate her average velocity.

.Name that motion