1. Physics 1 – Aug 23, 2019
P3 Challenge – Do Now (on slips of paper)
The length of a rectangle is measured to be /- 0.3 cm while its width is measured to be 6.2 +/- 0.3 cm. What is the area of the rectangle with its propagated uncertainty?
Get out 1.2 WS p2-4 for
HMK check

2. Objectives and Agenda Objectives
1.2 Uncertainties and Errors
Assignment: One graph to process from video
Agenda
Error in Graphs
Homework Review
Graphing Density of Water Lab Overview (time permitting)

3. Graphing Error Analysis Overview
Determine two points on each max/min line generated from the extreme point error boxes
Use algebra to determine the slope and intercept of the max and min lines
Find the (max – min)/2 for slope to determine the uncertainty in the best fit slope.
Find the (max – min)/2 for the intercepts to determine the uncertainty in the best fit intercept.
Write summary equation for the best fit line with uncertainties.
Determine the percent error, if appropriate.
Decide on IV and DV variables.
Title the graph and the two axes.
Decide on scales for both axes.
Plot points.
Draw error bars for extreme points (or all)
Draw best fit line.
Find two points on best fit line.
Use algebra to find slope of and intercept of the best fit line.
Draw the max and min slope lines
Animation of the process and practice

4. Graphing Lab Overview
Collect Mass and Volume Data for water for volumes of APPROX 5, 15, 25, 35, 45 mL. (be sloppy)
Record the actual volume used as accurately as possible. (Do NOT use exactly 5.0 mL etc…)
Record the mass to 3 decimal places using a triple beam balance. (be very sloppy)
Share your data with the class on the board and copy all class data.
Find ave and std dev of all volume and mass data. (Divide and conquer.)
Plot points (mass vs volume) with error bars for each point reflecting std devs
Determine min/max lines to asses uncertainty in slope and intercept.
Determine best fit line with uncertainties for the density of water.
Compare results to accepted 1.00 g/mL with a % error.

5. Exit Slip - Assignment
Exit slip – Describe how one determines the uncertainty in the value of a slope that is determined graphically.
What’s Due? (Pending assignments to complete.)
Complete the graph and data processing for the Graphing Lab Activity.
What’s Next? (How to prepare for the next day)
Read IB 1.2 p 11-20