Motion pt 2
Table of Contents 1. FTF s 2. Forces and Motion Phet Lab 3. Bill Nye: Gravity 4. Brainpop (Forces) 5. Lab: What Law Is It? 6. HW: Ch 3 7. Cartoon or Poem (2 nd Law) 8. Explorations Ch 2 & 3
FTF Day 1 Feb 2, 2012 HW: Ch 3 Review Q s and Key Terms (Friday) Topic: Newton s 2 nd and 3 rd Laws Questions If I push against a wall with a force of 20 N, how much force is the wall exerting on my hand? Draw a force diagram for your hand.
Activities Go over future folder requirements Go over Forces and Motion Lab (plus post lab activity) Learn 2 nd and 3 rd laws of motion Prepare for tomorrow s lab
Folders Must have a table of contents Must be in order according to table of contents. Must be in a binder (paper w/brads OR 3 ring) It is your responsibility to obtain work you missed. NOT during class time Before school after school During A-lunch by appointment or during homeroom
Two types of friction: static friction and kinetic friction Static friction - resists an object to start moving or sliding Kinetic friction - resists an object that is already moving or sliding and always acts in a direction opposite of the motion (the reason that anything sliding freely will eventually come to a stop) Note: static friction is always stronger than kinetic friction
Acceleration Acceleration measures how fast an object changes velocity. Measured in units like this m/s/s or m/s 2 (Meters per second per second) Unbalanced forces cause an object s velocity to change.
Instructions Google search forces and motion phet Click on the first link. Click on run now
Acceleration Acceleration = measures how much an object s velocity changes over time. is it going faster? Is it slowing down? Is it turning? What causes an object to accelerate? Unbalanced forces http://phet.colorado.edu/en/simulation/forces-and-motion
Slow Fast
Acceleration due to gravity: 9.8 m/s/s For a ball in free-fall: Every second that goes by, the ball s velocity increases by about 10 m/s.
Newton s 2 nd Law of Motion F = M A Force = Mass x Acceleration Greater force means greater acceleration. Greater mass means you need greater force to accelerate an object an equal amount.
F = M A Greater force means greater acceleration. Greater mass means greater force is required to accelerate an equal amount.
Newton s 3 rd law of Motion Every action has an equal and opposite reaction
FTF Day 2 Feb. 3, 2012 HW: none Topic: Lab: What Law Is It? Questions: What are the units we use for Force Mass Acceleration
Lab: What law is it? Activities
FTF Day 3 Feb 6, 2012 HW: Ch. 4 Key Terms and Review Questions (Friday) Topic: 2 nd and 3 rd law Questions: Apply Newton s 2 nd Law (F=MA) to a situation you encountered this week. Be ready to share!
Activities Chose one of the three activities: 1. Create a Sunday Morning Cartoon to illustrate F=MA (Newton s 2 nd Law of Motion) 2. Write a poem or song. Must be at least 12 lines long and rhyme. 3. Write the transcript for a sports broadcast that includes 7 out of 10 of the following terms: Acceleration, Friction, Mass, Inertia, Force, Kilogram, Newton s 2 nd Law, Free Fall, Newton, Velocity.
FTF Day 4 Feb 7, 2012 HW: (CH 4 DUE NEXT WEEK) - complete Explorations Ch. 2 & 3 packet by Friday Topic: Newton s 2 nd and 3 rd Law Questions: What is the acceleration of gravity? If you drop an object off a cliff, how much will its speed increase every second that its falling? (assuming no air resistance)
Activities Mass Vs. Weight Brainpop Video - Acceleration In groups, work on Explorations packet Circus Physics Video
Nova video Circus physics http://video.pbs.org/video/1607925512/ Brainpop Acceleration http://www.brainpop.com/science/motionsfo rcesandtime/acceleration/
FTF Day 5 Feb 8, 2012 HW: Explorations Ch. 2 & 3 Packet (Friday) Topics: 2 nd and 3 rd laws of motion Questions - You throw a ball straight up in the air. The ball leaves your hand going 20 m/s. How long will it take the ball to slow down to 0 m/s? How high will the ball go?
Second part of FTF Question. If you throw the ball off a cliff with a downward speed of 20 m/s, how many seconds will it take the ball to accelerate to 50 m/s?
Activities Watch circus physics video (the one we didn t watch yesterday) Explorations packet: Finish 1 st and 2 nd page, begin working on 3 rd page. Demos Story time (if there s time)
Demo 1 Golf Ball vs. Fake Golf Ball Two balls are dropped at the same time. One has a mass of 20 g. The other has a mass of 200 g. Air resistance is the same for both balls. Which ball will hit the ground first? Prediction Observation Explanation
Hammer vs feather Here's the famous footage of the Apollo 15 astronaut that dropped a hammer & feather on the moon to prove Galileo's theory that in the absence of atmosphere, objects will fall at the same rate regardless of mass. 10 m/s = acceleration of gravity http://www.youtube.com/watch?v=5c5_doeyafk
Demo 2 Heavy Cart vs. Light Cart Cart with a cannon is launched down a ramp two times. First time: it hits a light cart. Second time: it hits a heavy cart. Compare the acceleration of the light cart to that of the heavy cart.
Demo 3 5, 4, 3, 2, 1.. Lift-off! A ball is shot straight up out of the cannon on top of the cart. What will happen when the cart is standing still? What will happen when the cart is moving?
Demo 4 How High? A golf ball is shot straight up out of a vertical cannon. A plastic, lighter ball is also shot straight up by the cannon. Equal force is exerted on the two balls with different masses. Compare the upward acceleration of the two balls.
Monkey and a Gun (Just for fun) A stuffed monkey is suspended from a rod at one end of a lecture hall by an electromagnet. A golf ball gun aimed directly at the monkey cuts power to the electromagnet when fired. Thus, the monkey begins falling at the same instant the gun fires the golf ball. http://www.youtube.com/watch?v=cxvshnrxljw
Monkey and a Gun (Just for fun) The projectile and target meet in mid air. Intuitively one might think that the ball will go over the monkey's head due to its fast speed. However, gravity accelerates all objects downward at the same rate, meaning the monkey and the ball will meet at exactly the same point. If the ball was shot even faster, it would still hit the monkey, but higher above the ground. No animals were harmed in this demo.
Bicycle Wheel (Just for fun) A bicycle wheel is suspended from one of end of its axie by a rope, and spun up by hand. The wheel's axle is then placed horizontally and the free end of the axle processes about the supported end. The gyroscope seems to defy gravity because the torque created by the spinning wheel counteracts the torque due to gravity. Gyroscopes have been used through history for varied uses such as stabilizing spacecraft or for guidance systems on ships and missiles. http://www.youtube.com/watch?v=8h98bgrzpom
FTF Day 6 Feb 9, 2012 HW: Finish Explorations Ch. 2 & 3 (Friday) Topics: 2 nd and 3 rd Law Questions: 1. If I push a 1 Kg cart with 20 N of force, how much force is the cart exerting on my hand? 2. What will the acceleration of the cart be if there is no friction? Force = Mass x Acceleration 3. What will the acceleration of the cart be if the force of friction is 10 N? Find Net Force First!!
Activities Work on explorations packet individually (20 min.) Ask questions about packet (15 min.)
Help with packet Equation to solve for the average speed is DIFFERENT for an object that s going at a constant speed than for one that is accelerating. For an object that is accelerating: Average Speed = (Final Speed + Initial Speed)/2 Distance = Average Speed x Time
No FTF today Feb 10, 2012 HW: None Topic: Finish Packet, Friction Questions: Update Table of Contents
FTF Day 8 (Sub was here) Feb. 13, 2012 Complete Ch 4 Key terms and review questions 1-10
FTF Day 9 Feb 14, 2012 HW: Ch 4 Review Questions 11-20 Topics: Physics in space, Newton s 3 rd law Questions: Describe the forces required to slow down a car. (At least 2) What formula can we use to predict how fast the person on the skateboard will move away from the wall?
Happy Valentines Day! Describe Make-up Folders that live by the homework basket. Pass back papers (are you missing work?) Watch video about astronauts and the 3 rd law of motion. Complete a reading and answer 3 questions.
Video http://www.teachersdomain.org/resource/phy03.sci.phys.mfw.asrnt/
FTF Day 10 Feb 15, 2012 HW: Ch 4 review questions 11-20 (Tomorrow) Topics Review chapter 4 Questions: none
FTF Day 11 Feb 16, 2012 HW: Study Guide (Tomorrow) Test Wednesday Topic: Study techniques, 2 nd and 3 rd law Questions: Why do some things fall more quickly than others on earth if the acceleration due to gravity is always 9.8 m/s 2? (feather and a hammer example) If a ball is thrown straight up in the air, what is the acceleration of the ball at the very top of its flight?
Activities Discuss alternative plan for those who perform well on the study guide. Study guide work independently
FTF Day 12 Put study guide out on your desk while you do the FTF today. Feb 17, 2012 HW: Have a great weekend! Topics: Go over problems on study guide Questions: Make a prediction about the demo Which car s velocity will change the most: The Smart Car or the Mack Truck?
Grade study guide Activities Rate each question with regards to its difficulty * easy got it right without help ** so so - could figure it out with a little help *** challenging - needed a lot of help **** I had no idea how to solve this one Add up the stars on your sheet write score at the top of the page next to your name
Turn in Study guide (with score at the top) Ch 4 Key Terms & Review Q s 1-10 Ch 4 Review Q s 11-20
FTF Day 13 Feb 20, 2012 Topic: Laws of motion HW: Test on Wednesday Group 2 Students: Design a Study Due Thursday Group 1 Students: make a clues sheet and flash cards. No Questions
Activities Group 2 Students: Start research on Air Resistance Group 1 Students: Review
FTF Day 14 Feb 22, 2012 HW: Make clues sheet and study for test Test on Thursday Group 1: Complete Practice Problems Group 2: Design a study Due Monday Topic: Review No questions today
Activities Group 1: work on practice problems with help from teacher Group 2: Work on designing a study of air resistance (wait for explanation)