December 10, 2012

1. December 10, 2012 No notebook page today…. Take out: • PACKET 7 • SIGNED PROGRESS REPORTS (due tomorrow)

2. Evaluating Graphs of Motion- Page 7 • 4.4 TSW draw and interpret diagrams and graphs representing an object’s motion. • The slope of a line is how much it is on a tilt/angle • Complete the following sentences: (Distance vs. Time) • If the slope stays the same, the object is… • Moving at a constant speed • If the slope gets steeper, the object is… • Positively accelerating • If the slope gets lower, the object is… • Negatively accelerating

3. DISTANCE vs. TIME GRAPHS • X-Axis (bottom): Time • The further to the right on the axis, the longer the time from the start. • Y-Axis (side): Distance • The higher up the graph, the further away from the start position. • If an object is not moving, what would the graph look like? Describe the graph. • A horizontal line • Time is increasing to the right, but its distance does not change. It is not moving. We say it is At Rest.

4. If an object is moving at a constant speed, it means it has the same increase in distance in a given time. • As you move to the right, what happens? • Time increases • As you move up, what happens? • Distance increases • Do you think the object is moving at a constant speed? • Yes. Constant speed is shown by straight lines on a graph.

5. Two moving objects: • Are the speeds changing or constant? Explain. • Both lines are straight, so both speeds are constant. • What does a steeper line indicate? • A larger distance moved in a given time = higher speed • Did the objects move the same distance or different? • Each object moved the same distance • Which line got to the destination first? • The steeper, dashed line

6. Acceleration: Graphs that show acceleration are not straight lines (like constant speed). • What does this graph show about the speed of the object? • An increase in speed, since the line is getting steeper. • What is it called when, in a given time, the distance the object moves is changing (getting larger). • Positively accelerating • How would you show negative acceleration?

7. How would you show an object that left home, and then came back home? • Leaves home • Stops somewhere • Goes back home

8. Summary: Distance-Time Graphs • A distance-time graph tells us how far an object has moved with time. • The steeper the graph, the faster the motion. • A horizontal line means the object is not changing its position - it is not moving, it is at rest. • A downward sloping line means the object is returning to the start. A Word Bank: Returning to Start Getting Faster Steady Speed Stationary Fast, Steady Speed E C B D

9. Try the rest of the page • With a table partner • Stop when finished with page….do NOT go on!

10. Distance vs. Time- Motion of a Truck- Page 7 • How far is the truck from its starting point after: • 10 s _________ • 15 s _________ • 30 s _________ • 43 s _________ • 50 s _________ 300 m 300 m 200 m 660 m 800 m

11. Distance vs. Time: Motion of a Horse • horse travels fast (gallops) then changes to slower speed (trot)          • horse travels fast (gallops) then stops • horse travels slowly (trot) then changes to higher speed (gallops), stops, then speeds off quickly (gallops)

12. Distance vs. Time: Motion of a Train • train travels slowly then changes to higher speed (accelerates), then slows down (decelerates) • train travels faster and faster (accelerating)  • train travels fast then slows down (decelerating)      

13. Distance vs. Time: Motion of soccer player • player runs fast, stops, then runs fast back to starting point • player runs fast then immediately runs half-way back, then forward and back several times • player jogs slowly, changes to running speed (accelerates), then slows down (decelerates) to a stop and reverses direction coming back to the starting point

14. Evaluating Graphs of Motion- Page 7 • Speed vs. Time • Complete the following sentences: • If the slope stays the same, the object is… • Constantly accelerating • If the slope gets steeper, the object is… • Accelerating quickly • If the slope gets lower, the object is… • Gradually accelerating

15. SPEED vs. TIME GRAPHS • Speed-Time graphs look much like Distance-Time graphs. Be sure to read the axes labels!! • X-Axis: Time • Y-Axis: Speed or Velocity • What would a graph look like that showed an object at rest? • A straight, horizontal line and the speed = 0, directly on the time axis • What does a straight, horizontal line on a speed-time graph mean? • Speed is constant, not changing over time. Fast speed Slow speed

16. This graph shows increasing speed. Describe its motion. • The moving object is accelerating (positive acceleration). • This graph shows decreasing speed. Describe its motion. • The moving object is decelerating (negative acceleration).

17. Two moving objects. • Do the lines show increasing or decreasing speed? • Both the dashed and solid line show increasing speed. • Which line reaches a greater speed? • Both lines reach the same top speed • Which line takes longer to reach its top speed? • The solid one takes longer • Which line shows greater acceleration? • The dashed line shows a greater acceleration.

18. Summary: Speed-Time Graphs • A speed - time graph shows us how the speed of a moving object changes with time. • The steeper the graph, the greater the acceleration. • A horizontal line means the object is moving at a constant speed. • A downward sloping line means the object is slowing down. Word Bank: Steady Deceleration Steady Speed Gradual Acceleration Steady Acceleration C B D A

19. Try the rest of the page • With a table partner • Stop when finished with page….do NOT go on!

20. Speed vs. Time- Packet 7, Page 7 None!!! None!!! • Involve a time where the speed (velocity) of an object was held constant? • Involve a time where the acceleration of an object was held constant? • Positive acceleration (speeding up), then steady speed (velocity), then negative acceleration (slowing down), then Positive acceleration (speeding up)? • Steady speed (velocity), negative acceleration (slowing down), then steady speed (velocity)? • Constant positive acceleration? • Steady speed (velocity) then positive acceleration (speeding up)? • Positive acceleration (speeding up) then steady speed (velocity)? • Positive acceleration (speeding up) then negative acceleration (slowing down)? • Stopped for a while, then fast speed? • Fast speed then stopped for awhile?

21. Homework: Page 8- Graphing Motion • Distance-Time Graphs • Speed-Time Graphs

23. Objective 12/11/2012 Page 6 SWBAT relate the forms of energy to everyday life situations and creating roller coasters in groups. Jumpstart • What is the greatest speed the worm reaches? • What is the worm’s acceleration during the first 2 minutes? • How fast is the worm traveling as it goes from A to B? • How far does the worm travel from A to B? • What is the worm’s acceleration from A to B? • How does the worm’s motion change from B to C? • What is the worm’s acceleration during the last 2 minutes? • How would you describe the worm’s motion during the last 2 minutes?

24. Forms of Energy Packet Page 9 Notebook Page

25. Page 8 – Distance-Time & Speed-Time Graphs • A, E, F • D • B, C • E • B, C, D, E, F • F • 2.5 y/s; 5 y/s 5 y/s; 2.5 y/s 5 y/s; 2.5 y/s 5 y/s; 7.5 y/s 2.5 y/s; 2.5 y/s 7.5 y/s; 2.5 y/s • Constant speed • Coming back & Constant speed • Stopped • Speed Decreasing • Albert • Charlie • 5 seconds • 14 seconds • 100 m/12 s = 8.33 m/s • Accelerating • Slowing down • Constant speed • Stopped • Accelerating • Constant speed • Decelerating • At rest • Accelerating

26. Physics of Roller Coasters: Potential and Kinetic Energy Page 9 7.1 - TSW use an operational definition of energy. 7.2 - TSW demonstrate that energy can be kinetic or potential.

27. Potential and Kinetic Energy • Energy- the ability to do work • Unit: Joules (J) • Kinetic energy (KE) – energy of motion • KE = ½ mv2 • KE = ½ × mass × velocity (squared) • KE = ½ × mass (kg) × velocity² (m/s*m/s) • REMEMBER: Velocity- the speed and direction of an object’s motion. • Potential energy (PE) – stored energy • PE = mgh • PE = mass × gravity × height from ground level • PE = Mass (kg) × 9.8 (m/s²) × height (m)

28. Can you identify the two different types of Potential Energy? • The massive ball of a demolition machine and the stretched bow possess energy. • Elastic Potential Energy- PE associated with objects that can be stretched or compressed • Gravitational Potential Energy- PE that depends on height

29. Types of Potential Energy When do children on a trampoline have Gravitational PE? When do they have Elastic PE? • Elastic Potential Energy: due to compressing or stretching—like a bow and arrow • Written PEelastic • Gravitational Potential Energy: due to height—like standing on a diving board ready to jump off • Written PEgrav

30. Mechanical Energy (ME)- A combination of kinetic and potential energy • ME = total KE + total PE • A roller coaster is simply a closed system in which there is a constant transfer of potential energy and kinetic energy. • Law of Conservation of Energy– energy cannot be created or destroyed, only transformed from one form into another

31. December 12, 2012 • Open Packet 7 to Page 9 • Thrill Ride- Page 17 in booklets

32. Examples

33. Roller Derby Challenge

34. Homework: Page 10- Potential and Kinetic Energy Energy Basics What is Energy?