Collect handouts 2 problems collected from HW A today – JUST checking notation. 2 pts each. –1.35, 1.42 Measurements lab due Monday. Homework B due Tuesday. Test on this stuff on Thursday. (Test does NOT cover lab materials.)

Measurements Lab Requirements pt 1 What you should have finished in lab on Wednesday: (if you need more time, let me know ASAP) 1.Measure inside & outside diameters of graduated cylinder. 2.Measured mass of metal cylinder 3.Measured diameter of metal cylinder using micrometer 4.Measured height of metal cylinder using Vernier Caliper 5.Measured your knuckle width with Vernier Caliper & told me the value

Measurements Lab Requirements pt 2 What you should calculate: (show all work, preferably on another paper, if you want me to find your mistakes) 1.All values should have: value ± abs error units (% error) 2.Top box: row 3 should have 2 values: a subtraction (and errors), and a division (and errors). Follow rules for errors. 3.Bottom box: Calculate radius, area, volume, and density from the measurements. Each value should have absolute & percent errors and units calculated. Remember  water = 1 g/cm 3 for comparison. 4.(continued)

Measurements Lab Requirements pt 3 What you should calculate: 4.When ABSOLUTE errors are MEASURED, they should have 1 significant figure. The size of the absolute error is based on how well you think the tool works or how well you used it. 5.When ANY error is CALCULATED, use two significant figures. 6.Calculate the class average knuckle width, the standard deviation of the data, how many data values fit inside the 1  and 2  ranges, which range your knuckle is in, and answer the question at the bottom of the page. Download data from web page. [FOR YOUR OWN GOOD: See M & M data for examples of how to do these calculations.]

Review questions coming Similar to Quick Quiz 2 on page 31

An object is moving to the right. Which sign is its velocity? 1.Positive 2.Negative 3.Not enough info to answer

An object is moving to the right. Which sign is its position? 1.Positive 2.Negative 3.Not enough info to answer

An object is moving to the right. Which sign is its acceleration? 1.Positive 2.Negative 3.Not enough info to answer

An object is moving to the right and speeding up. Which sign is its acceleration? 1.Positive 2.Negative 3.Not enough info to answer

An object is moving to the left and speeding up. Which sign is its velocity? 1.Positive 2.Negative 3.Not enough info to answer

An object is moving to the left and speeding up. Which sign is its acceleration? 1.Positive 2.Negative 3.Not enough info to answer

Which of the following can be represented by negative acceleration? 1.Speeding up 2.Slowing down 3.Being stopped 4.Both 1 & 2 5.All of the above What does the book say on page 29?

Graphs Review rules for x-t & v-t graph Show an accelerating object on v-t graph –Clicker question (next slide) Show rules for v-t & a-t graph [negative area!] Average velocity equation For constant acceleration only: Acceleration equation Area under v-t graph equation Other equations of motion

At the end of the a-t graph shown, what is the velocity? Positive (which means moving which way) 2.Negative (which means moving which way) 3.It is stopped

At the end of the a-t graph shown, what is the acceleration? Positive 2.Negative 3.Zero

Acceleration graphs Do quick quiz 2.3 (page 32) with clickers. (next few slides) Do quick quiz 2.4 (page 34) with clicker (slide after)

Refer to page 32, figure Top row = v-t graphs. Bottom Row = a-t graphs. Which in bottom matches with “a”? 1.Don’t pick 2.Don’t pick 3.Don’t pick 4.D 5.E 6.F

Refer to page 32, figure Top row = v-t graphs. Bottom Row = a-t graphs. Which in bottom matches with “b”? 1.Don’t pick 2.Don’t pick 3.Don’t pick 4.D 5.E 6.F

Refer to page 32, figure Top row = v-t graphs. Bottom Row = a-t graphs. Which in bottom matches with “c”? 1.Don’t pick 2.Don’t pick 3.Don’t pick 4.D 5.E 6.F

Refer to page 34, figure Which graph is physically impossible? Select all that apply. 1.A 2.B 3.C

After working on the handout a bit Quick Quizzes 2.6, 2.7 with clickers. Quick Quiz 2.8 is a good question to help you understand acceleration.

A tennis player on serve tosses a ball straight up. While the ball is in free fall, does its acceleration: Increase the whole time 2.Decrease the whole time 3.Increase then decrease 4.Decrease then increase 5.Remain constant

As the tennis ball travels through the air, its speed: Increases the whole time 2.Decreases the whole time 3.Decrease then increase 4.Increase then decrease 5.Remain constant