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GRAVITY Warm Up: 1. What are your ideas about gravity? ◦What is it? ◦What causes it? ◦What changes it? ◦How does it affect things? 2. What variables do you think affect gravitational force? Objective/ SWABAT: Predict how the gravitational force between two bodies would differ for bodies of different masses or different distances apart. WA St Standard PS1F Explore what affects gravity using Gravity Force Lab applet 1. Go to: http://phet.colorado.edu/en/simulation/gravity-force-lab 2. Click the to run the program. 3. COPY and Answer questions 1-6 in your journal http://www.universetoday.com/34824/force-of-gravity/ Homework Read Take DETAILED Notes GRAVITY Warm Up: 1. When considering gravity, where is the distance between the objects measured from? 2. What is an independent (manipulated) and dependent (responding) variable? Hint: DRY MIX Collect and graph data Today you will create three graphs relating independent variables to the gravitational forces experienced by the objects. These graphs will be turned in. GRAVITY Warm Up: DRY MIX What is that? What does it help us recall? How does it apply to graphing? Graph data Today you will create three graphs relating independent variables to the gravitational forces experienced by the objects. Tomorrow these graphs are due! If you complete these graphs. Please begin on the questions 1-9, due Friday. GRAVITY Warm Up: Show me your amazing graphs 1. Get out the graphs you created 2. Check to make sure each has labeled axes, title, units, data table, trend line and YOUR NAME 3. What does this graph mean? Whiteboard and Interpret In 6.42 minutes…or less to prepare, then we will present the whiteboards. 1. Graph the shape of your assigned independent variables to the gravitational forces experienced by the objects. 2. Write 2 statements that describe the relationship of the variables graphed 3. Present your board What does this shape tell us about the relationship of gravity and distance? GRAVITY Discuss with your group which two variables you believe affect gravity the most. Review of Gravity Today in class… Reading assessment #3 Questions 1-9, due stapled to graphs Monday Objective/SWBAT: Explain how weight of an object can change while its mass remains constant. WA St Standard PS1F Can you calculate the attractive force you and the Earth experience because of each other? Careful with units! •Radius of the Earth is 6,371 km. (needs to be in meters) •Mass of the Earth is 5.974 x 10^24 kg. •1 kg = 2.2 lb •N= (kg m) /s2 School House Rocks GRAVITY http://www.universetoday.com/34824/force-of-gravity/ White board your portion Whole class Take DETAILED Notes Today in class… Questions 1-9, due stapled to graphs Monday- hey that’s today! Calculate the attractive force you and the Earth experience because of each other. Careful with units! •Radius of the Earth is 6,371 km. (needs to be in meters) •Mass of the Earth is 5.974 x 10^24 kg. •1 kg = 2.2 lb •N= (kg m) /s2 School House Rocks GRAVITY GRAVITY Warm Up: What is acceleration? What causes an object to accelerate? How might acceleration relate to gravity? Acceleration 1. Acceleration is a change in direction or speed of an object. 2. Acceleration is caused by a net force acting on an object. Does this data show acceleration? What is causing the velocity to change? What is the shape of a velocity: time graph for this data? Position is changing at a NON-CONSTANT rate, Velocity is changing Velocity is changing at a CONSTANT rate, acceleration is constant Rate of acceleration is CONSTANT9.8 m/s2 on Earth Confused? Fg and g Fg is the mutual force created by the 2 objects interacting. g is the acceleration due to gravity. Paper, book, and a white board GRAVITY Entry task: Bowling ball and a Soccer Ball (on a half sheet with your name): Write a claim of which ball will hit the ground first. Then…Explain which will hit first a bowling ball or a soccer ball using force diagrams. 1. Draw 2 force diagrams. 2. One that shows the forces acting on a bowling ball as it falls. 3. The other showing the forces acting on a soccer ball as it falls. Bowling ball or soccer ball? Aristotle vs Galileo Brainiac Video https://www.youtube.com/watch?v=AYz_K3mwq6A What falls faster? A feather or a bowling ball? https://www.youtube.com/watch?v=E43-CfukEgs Falling Objects misconceptions https://www.youtube.com/watch?v=_mCC-68LyZM Exit ticket Explain which will hit first a bowling ball or a soccer ball using force diagrams. 1. Draw 2 force diagrams. 2. One that shows the forces acting on a bowling ball as it falls. 3. The other showing the forces acting on a soccer ball as it falls. 4. Add a statement about what might change with terminal velocity GRAVITY Free Fall- the affect of acceleration and inertia http://www.telegraph.co.uk/news/science/space/9849206/Felix-Baumgartner-fell-faster-thanwe-thought-supersonic-skydiver-hit-Mach-1.25.html http://arstechnica.com/science/2012/10/skydiver-breaks-speed-of-sound-after-jumping-fromedge-of-space/ Terminal Velocity https://www.youtube.com/watch?v=9imImfmt2BE GRAVITY Warm Up: Make sure you have the value of “g” written in your notes. Notes can be used on the Quest tomorrow. Now that you know the acceleration due to the force gravity is 9.81 m/s2… I bet you are wondering where that number comes from, right? Astronauts Feather and Hammer https://www.youtube.com/watch?v=-4_rceVPVSY See how “g” applies ? ? Do you weigh the same on Earth and the moon? Why is that? Mass and weight are different- I’m going on a moon diet Putting it all together… 1. What 3 variables affect gravitational force? 2. What is Newton’s Law of Gravitation? 3. What is Newton’s second law? g = 9.81 m/s/s You may calculate the gravitational force on the astronaut on the Earth given the Following: Radius of the Earth 6,371,000 m Mass of the Earth 5.974 x 10^24 kg Putting it all together… Why is it that the weight of the astronaut changes? What 2 variables affect gravitational force? What is Newton’s Law of Gravitation? What is Newton’s second law? g = 9.81 m/s/s You may calculate the gravitational force on the astronaut on the moon given the Following. Radius of the Earth 6,371,000 m Radius of the Moon 1,737,100 m Mass of the Earth 5.974 x 10^24 kg Mass of the Moon 7.347 x 10^22 kg Write it on you whiteboard. Show your math. g=? Calculate weight (force due to gravity) in the following problems by using the equation: weight = mass x free-fall acceleration w=mg g (on Earth) = 9.8 m/s2 (1) ALWAYS write the equation (2) plug in the numbers and units, (3) give the answer with the correct units. 1. A physical science text book has a mass of 2.2 kg a) What is the weight on the Earth? b) What is the weight on Mars (g = 3.7 m/s2) 2. If the textbook weighs 19.6 newtons on Venus, What is the strength of gravity on Venus? 3. Of all the planets in our solar system, Jupiter has the greatest gravitational strength. If a 0.5 kg pair of running shoes would weigh 11.55 newtons on Jupiter, what is the strength of gravity there? 4. If he same pair of shoes weighs 0.3 newtons on Pluto, what is the strength of gravity on Pluto? 5. What does the pair of shoes weigh on Earth? Quest Review GRAVITY http://www.history.com/shows/theuniverse/videos/the-universe-gravity Senate Constitutional Convention: The Universe: Gravity Episode Please answer the Guided Questions GRAVITY