CHAPTER 1, SECTION 5Negative Acceleration: Braking Your Automobile

Do Now

A car is traveling at 60 m/s, the driver sees a stoplight ahead and slows to a complete stop in 10 seconds. What is the car’s acceleration?

A motorcycle is passing a bus on a two lane highway and increases his speed from 40 m/s to 75 m/s in 5 seconds. What is the motorcycle’s acceleration?

Date: September 4, 2012HW: PTG pg. 88, #1-4, Due Friday Do Now (NB pg ?): WDYS WDYT

TB pg. 75 Read Investigate #1-4

TB pg. 76-77

Agenda: Do Now Objective & Success Criteria Investigate Physics Talk Quiz 1.5 PTG

Learning Objective: Explain how negative acceleration relates to braking and stopping distance

Success Criteria: Plan and carry out an

experiment to relate braking distance to initial speed

Determine braking distance Examine accelerated

motion

Investigate: Initial Speed and Braking Distance Materials:

List all materials for your lab today.

How will you use these materials to test initial speed and braking distance?

Investigate

Hypothesis:

With your group come up with a hypothesis for initial speed and braking distance using:

IF__________THEN__________BECAUSE____________statement

Investigate:

Complete #1-3 with your group Check procedures with Mr. LePera Create data table Check with Ms. LePera

HW:PTG pg. 88, #1-4, Due Thurs

Finish procedures and data table Set up and collect data

Remember you are measuring the SPEED at the bottom of the ramp and BRAKING distance in METERS!

Analyze Data Average speed AND distance for EACH

height

HW:PTG pg. 88, #1-4,

Do Now: Find Averages Complete #5 a ,b on pg.

77 One group member draw

your graph on the board Complete #5c-e

Agenda: Do Now Investigate 5-8 Physics Talk

Checking up Quiz

Learning Objective: Understand how negative acceleration relates to braking and stopping distance

Success Criteria: Plan and carry out an

experiment to relate braking distance to initial speed

Determine braking distance Examine accelerated

motion

Investigate #5-8

As a class

Physics Talk

What is negative acceleration?

Draw an example of negative acceleration

Change in velocity with respect to time by decreasing speed in the positive direction or increasing speed in the negative direction

Physics Talk

How do you calculate braking distance?

Vi2=-2ad

vi2

-2a d

Checking up pg. 82, #1-3

HW: None Do Now:

Get out 1.5 PTG #1-4 Discuss answers with

your group

Agenda: 1.5 PTG #1-4 1.5 Quiz Computer Set up (p4) Chapter Challenge Rubric Chapter Challenge Work

Day

Learning Objective: Understand how negative acceleration relates to braking and stopping distance

Success Criteria Calculate negative

acceleration and braking distance

Work on Chapter Challenge