evaluate the graph - siena collegetitle phys130_ch2_d1.ppt author michelem created date 8/19/2012...
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![Page 1: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/1.jpg)
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Evaluate the Graph
• Give a verbal description of the motion • Rank in order the speeds at points A, B, and C, from
slowest to fastest. • Draw a velocity-versus-time graph (including the correct
numerical scale)
B
A C
![Page 2: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/2.jpg)
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Evaluate Graphs
• For each graph, answer the following question. • Do A and B ever have the same speed? If so, at what
time or times?
B
A B A
![Page 3: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/3.jpg)
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Motion Activity
• Use a motion detector with the LoggerQuest • Motion Activity - One member of each group walks • at a steady speed away from the motion detector • at a steady speed toward the motion detector • at an increasing speed away from the motion detector • at a decreasing speed away from the motion detector • at an increasing speed toward the motion detector • at a decreasing speed toward the motion detector
• For each, sketch diagrams, position graphs, and velocity graphs
• To change time, switch modes so that the choices are File and Sensor, then select Data Collection
![Page 4: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/4.jpg)
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Tactics: Interpreting position-versus-time graphs
![Page 5: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/5.jpg)
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Finding Position from Velocity If we know the initial position, si, and the instantaneous velocity, vs, as a function of time, t, then the final position is given by
Or, graphically;
![Page 6: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/6.jpg)
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Back and Forth
acceleration
velocity
position
acceleration
velocity
position
derivative
derivative
integral
integral
area
area
slope
slope
![Page 7: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/7.jpg)
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EXAMPLE 2.7 The displacement during a drag race
![Page 8: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/8.jpg)
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Find Area Graphically
• Using the graph, find the position at t = 1, 2, 3, 4, and 5 s and make a table.
• From this data, draw a position-versus-time graph
![Page 9: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/9.jpg)
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Find Area Graphically
• A train is moving at a steady 30 m/s. At t = 0s, the engine passes a single light at x = 0 m. Without using any formulas, find the engine’s position at t = 1 s, t = 2 s and t = 3 s.
• Graph position and velocity versus time • Find the area from the velocity-versus-time graph
• Δs = area under the velocity-versus-time graph
![Page 10: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/10.jpg)
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Position-Versus-Time
• Trucker Bob starts the day 120 miles west of Denver. He drives east for 3 hours at a steady 60 miles/hour before stopping for his coffee break.
• Draw a position-versus-time graph for Bob, including appropriate numerical scales along both axes.
• Let Denver be located at x = 0 and assume that the x-axis points to the east.
![Page 11: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/11.jpg)
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Uniform Motion
Straight-line motion in which equal displacements occur during any successive equal-time intervals is called uniform motion. For one-dimensional motion, average velocity is given by
Notice the symbol Δ. It represents a displacement and an interval in time - not position or instant in time
![Page 12: Evaluate the Graph - Siena CollegeTitle Phys130_Ch2_D1.ppt Author michelem Created Date 8/19/2012 7:14:37 PM](https://reader033.vdocument.in/reader033/viewer/2022041602/5e31f061bd30c05b9958deb0/html5/thumbnails/12.jpg)
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Problem Solving Strategy
• Sally opens her parachute at an altitude of 1500 m. She then descends slowly to earth at a steady speed of 5 m/s. How long does it take her to touch down?
• Draw pictorial representation – coordinates, symbols • Motion diagram • Mathematical Representation • Are results reasonable?
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