Physical Science CHS 2013-14 UNIT 2 Motion, Forces, Energy
10/3/13 • Entry Task • If a car travelled 60 miles and it took the car 2 hours, how many miles per hour was its average speed? • Mathematically speaking, what does the “per” in the above question mean? • REMEMBER! All missing work for unit due tomorrow! • HOMEWORK – start WHEN FINISHED WITH TEST: Read pages 76-80. Answer all questions #1-10 on page 80. Due Monday 10/7/13
Today’s Agenda • Students needing more time on the test will be finishing their tests. • HOMEWORK – start WHEN FINISHED WITH TEST: Read pages 76-80. Answer all questions #1-10 on page 80. Due Monday 10/7/13 • PLEASE BE RESPECTFULLY SILENT AND SEATED until all tests are turned in. • EXTRA TIME? Complete the “Designing an Investigation” Crossword for extra credit
10/3/13 • Exit Task • What is your average speed if you walk 4 kilometers in 4 hours? • Hint: speed =
10/4/13 • Entry Task • Say Something Nice • For 2 free points! • “What does the fox say?” • Reminder HOMEWORK –: Read pages 76-80. Answer all questions #1-10 on page 80. Due Monday 10/7/13
Today’s Agenda – take notes with a partner pages 76-85…complete as HOMEWORK! Vocabulary – give meaning in own words How is velocity different than speed? How do you show forwards and backwards movement? What is the difference between “distance” and “change in position? What does a straight line mean on a position vs time graph? How can you recognize a relationship on a graph? How do you calculate slope? What does slope also indicate? Sketch a position vs time graph. Sketch a speed vs time graph • Speed • Average Speed • Instantaneous Speed • Velocity • Distance • Constant speed • Slope Key Ideas – take notes on these ideas What is the difference between average speed and instantaneous speed?
10/4/13 • Exit Task • Trade and Grade week of 9/30-10/4 • 2 more free points for your HIGH INTEGRITY grading • Please be sure to only give points when it is earned! • Reminder HOMEWORK –: Read pages 76-80. Answer all questions #1-10 on page 80. Due Monday 10/7/13 • PLUS – C-notes vocab AND key ideas pages 76-85. Also due Monday 10/7/13
10/7/13Week of 10/7 to 10/11 • New Seating Chart • Entry Task • Dino can leap 400 meters in 30 minutes. This includes brief sprints to catch butterflies. What is his average speed in m/min? • What is his average speed in m/hr? • Can you tell his velocity? Why or why not?
Today’s Agenda • Please get out p. 80 homework #1-10. • Trade and Grade. • Please also get out your C-notes vocab and key ideas pages 76-85. • Brief review with name cards…. • Turn in all homework! • See next slide…planning an investigation.
Planning a Speed Investigation • You will choose the independent variable. • GOAL: find a way to increase the velocity of the car once it crosses the photogate at bottom of ramp. • Write down your independent variable choices: • Adding mass - mass balls – 1,2,3 • Placement of mass balls – front, middle, rear hole • Rubber bands – distance stretched - • # of rubber bands – 1,2,3 • Height of ramp • Placement of photogate – high, medium, low • Temperature of car – cold, warm, hot • Oil on axle – light, medium, heavy application
GREEN SHEET – Designing an Investigation • You will each complete all portions listed on green sheet in your composition notebooks. • TITLE • Identify variables • Question • Hypothesis • Materials and PROCEDURE • Be thorough and thoughtful with this section! • 3 trials for each of 3 conditions • Experimental Control Condition • Extra Validity Measures • DATA TABLE – I will post this…you add your groups labels and measurements. • Have design finished for tomorrow! Approval by start of class tomorrow…
10/7/13 • Exit Task • What independent variable did your group choose? • What is your Hypothesis?
10/8/13 • Entry Task • What is the “experimental control condition”? • What are “extra validity measures”? • For this lab, what will you do for both of the above?
Today’s Agenda • Get approval for your lab design before you begin • Be sure your data table is complete • Be precise in your measurements. • Complete data collection and calculating averages and speed today. • EXTRA TIME? Begin designing your graph.
10/8/13 • Exit Task • What 3 controlled variables did you include in your lab design?
10/9/13 • Entry Task • We have calculated speed for our current lab: speed = • Why do you keep distance as 1 cm? • Hint: how wide is the flag on the car? • HOMEWORK: Speed Practice Sheet. Due Friday 10/11/13
Today’s Agenda • EACH PERSON WILL: • Collect and record data with their team. Create a graph of your results – consult green sheet. • Draft and write conclusion – consult green sheet. • IN THEIR COMPOSITION NOTEBOOKS
10/9/13 • Exit Task • Begin your conclusion from your data… • Answer your investigative question, “How does( your chosen independent variable) • affect speed through the gate?” • Was your hypothesis supported? • HOMEWORK: Speed Practice Sheet. Due Friday 10/11/13 • Review Rubric
10/10/13 • Entry Task • If I told you an object ACCELERATES 9.8 m/s each second and I let it drop from a standstill… • How fast would it be going after 1 second? • Draw a picture to help you! • REMINDER HOMEWORK: Speed Practice Sheet. Due Friday 10/11/13
Today’s Agenda • Complete graphs. • Complete conclusions • Share good student examples. • See how many points you will get. • Partner Discuss • Fix yours where you need to. • Be ready to turn in tomorrow.
10/10/13 • Exit Task • What does “acceleration” mean? • How is this different than speed? • REMINDER HOMEWORK: Speed Practice Sheet. Due Friday 10/11/13
10/11/13 • Entry Task • Say Something Nice • For 2 free points! • DUE DATES EXTENDED!!! • HOMEWORK: Speed Practice Sheet. Due Monday 10/14/13 • SPEED LAB: Due Monday 10/14/13
Today’s Agenda • Pre-assessment of understanding of Motion, Forces, Energy. • Your score will NOT be your grade. • You are graded on effort and completion. • At the end of the unit, you’ll be given a similar assessment and you can track your growth!
10/11/13 • Exit Task • Trade and Grade • For 2 free points…
10/14/13Week of 10/14 to 10/18 • Entry Task • Which unit would you use with acceleration? • Why is the bottom letter “squared”?
Please take out your homework… • Trade and Grade math problems. Grader sign at top. • DO NOT COPY ANSWERS FROM BOARD = cheating. • Self-assessment of lab investigation. • See Ms. Maring’s example. • Grade your own by carefully writing the points earned in the margin. • ALSO, circle on your rubric what you did not include. • PLACE YOUR RUBRIC in your comp book by the lab. Turn in to comp book shelves. I will lock them.
Today’s Agenda • Hand back papers and organize into binders. • If you are on the PASSING list for the Unit 1 test, you may design a lab based on one of the other independent variables. See sheet. • Form a team of 3-4 and collect data for that independent variable on the provided data table. • If you are in the REQUIRED REFLECTION group, you will join me for a discussion of the test
Passed Unit 1 test – “on your own” further investigative question lab • You will choose a different independent variablefrom this list… • Adding mass - mass balls – 1,2,3 • Placement of mass balls – front, middle, rear hole • Rubber bands – distance stretched - • # of rubber bands – 1,2,3 • Height of ramp • Placement of photogate – high, medium, low • Form a team of 3-4 with the same choice, write a brief lab design and collect data. • Please clean up and return materials when finished.
REQUIRED REFLECTION – Unit 1 test • If you had a score of 60% or below, you are required to reflect. • Please get out a piece of notebook paper. • Review reflection instructions. • You will be given the test back for this class period only. If you need more time, please schedule with me before/after school to use the test. • For each question you are seeking points back, • Write down the PROBLEM NUMBER and answer a, b, c, d. • The correct answer is shown in RED on your scan-tron paper. You may write down the answers on your written sheet. • You will staple your scan-tron and written section to your reflection.
10/14/13 • Exit Task • How could you show a change in velocity WITHOUT a change in speed? • What is another name for “change in velocity”?
10/15/13 • Entry Task • Please sketch a graph of the following (x axis time; y axis velocity) • From the river to the woods, Little Long-legs Red Riding hood accelerated from a starting velocity of 0.5 m/s to 1 m/s after 60 seconds. At the woods, she got scared and began running to grandmother’s house, accelerating from 1 m/s to 10 m/s in 30 seconds and then continued at that constant speed for the next 2 ½ minutes. • HOMEWORK DUE THURSDAY 10/17/13: Read pages86-93. Answer questions #1-11 on page 93. • REMINDER – you will need to bring your calculator EACH day for the rest of this unit!!!
STANDARDS – performance expectations • I can calculate the average acceleration of an object, given the object’s change in velocity with respect to time. (a =) • I can explain how an object moving at constant speed can be accelerating.
Acceleration • a change in velocity (speed or direction or both) over time • speeding up or slowing down • changing direction • moving in a circle is always changing direction
Changing direction http://phet.colorado.edu/en/simulation/moving-man
Negative acceleration • if acceleration is a negative number it is referred to as negative acceleration or deceleration Think “braking!”
The steeper the hill, the greater the acceleration… Very steep. Adding 2 m/s to the speed each second. Not very steep. Adding 1 m/s to the speed each second.
Zero Acceleration • there is zero acceleration at constant speed because the speed does not change. Think “cruise control”! (As long as direction stays the same…)
Math for Acceleration a = acceleration = speed at finish = speed at start t = time = time at finish = time at start Sometimes may simply be “t” a =
Same math as in your book…p 87 • Don’t write this down…
Example problem • A car is traveling at 3.4 m/s. After 3 seconds, it is now traveling 8.2 m/s. Calculate its acceleration. acceleration a = V1 = 3.4 m/s V2 = 8.2 m/s T = 3 seconds a = = 1.6 a =
10/15/13 • Exit task • A bike is traveling at 2.0 m/s. After 3 seconds, it is now traveling 5.0 m/s. Calculate its acceleration. HOMEWORK DUE THURSDAY 10/17/13: Read pages 86-93. Answer questions #1-11 on page 93. REMINDER – you will need to bring your calculator EACH day for the rest of this unit!!!
10/16/13 • Entry task • A bird is flying at 6.0 m/s. After 2 seconds, it is now flying 2.0 m/s. Calculate its acceleration. acceleration V1 = V2 = T = a =
Designing the Investigation • Question: How does placement of photogates affect acceleration of the car? • Make a prediction: • If the photogates are further apart • Then ________________________ • Because______________________ • Controlled variables:
Acceleration Lab • C-clamps at far top and far bottom of ramp. Ramp in 5th hole from bottom. • Photogate 1 will be at top black square mark. • Photogate 2 will be 10 cm below that. • Photogate 3 will be at first black mark below middle of ramp • Photogate 4 will be 20 cm below that. • Run car from top of ramp. Record time at each photogate. And Record time between photogates. Repeat for 3 trials. • Sit down to calculate averages, velocity and acceleration. • We will calculate velocity at photogate 1 as v1. • We will calculate velocity at photogate 2 as v2. • Then we can calculate acceleration as change in velocity with respect to time between photogate 1 and 2. • We will calculate velocity at photogate 3 as v1. • We will calculate velocity at photogate 4 as v2. • Then we can calculate acceleration as change in velocity with respect to time between photogate 3and 4.
10/16/13 • Exit Task • Did the car accelerate as it rolled down the ramp? In other words, were there changes in the car’s velocity over time (or between photogates)? • Use data from your data table to back up your answer! • REMINDER HOMEWORK DUE TOMORROW 10/17/13: Read pages 86-93. Answer questions #1-11 on page 93.