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Force and Motion 2/2 Weekly Highlander Sheet Objective: Apply Newton’s first law to real world scenarios. Responsibilities: Finish in class reading and Q’s Newton’s First Law Reading Answer Questions on worksheet and hand in. WHOT Q Tell a story of unbalanced forced in your life. Force and Motion 2/3 Weekly Highlander Sheet Objective: Students understand how to use a frame of reference to analyze movement. Responsibilities: Students will investigate to discover and identify evidence and various types of forces. Distance, Displacement, Frame of Reference Distance: the actual footpath Displacement: How far from the frame of reference. Frame of Reference: Location used to locate or measure movement of a point in space. Warm Up: At what velocity is the stick-guy inside the train moving? What is your frame of reference? Frame of Reference 1. What is a frame of reference? system for specifying the precise location of objects in space and time http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=140 2. How is it used to measure motion? 9 Notation Change in position This symbol is used to indicate the starting position of an object. “i” stands for initial. This symbol is used to indicate the end position of an object. “f” stands for final. This symbol is used to indicate change in position of an object. 1. 2. 3. How fast? Calculating Velocity Velocity is a speed in a given direction. Velocity is calculated using a change in position during a certain amount of time. ______________ = V (in a given direction) Time https://www.youtube.com/watch?v=DRb5PSxJerM Complete this assignment Due by the end of the period WHOT Q Frame of Reference Force and Motion 2/4 Weekly Highlander Sheet Objective: accurately and confidently describe a position over time graph. Responsibilities: Homework!!! Due Friday!!! Is displacement more like the length of a rope that is pulled tight or the length of a coiled rope? It is more like the rope that is pulled tight because it measures the shortest distance between two points. 17 Distance The length of the path between 2 points. 0……………………………….1 mile Total distance? 1 mile Total displacement? 1 mile 18 Displacement Is the direction from the starting point and the length of a straight line from the starting point to the ending point. 0………………………………………….1 mile Total distance: 2 miles Total displacement zero 19 How are displacements combined? Displacements are combined using vector addition. We added the 2 vectors for the car to calculate its total displacement: The car went 1 mile to the right Then back one mile For a total displacement of zero 1 -1 0 20 Set Up the Axes~ 1. Make x & y axes on a white board 2. Label (y) North, label (–y) South 3. Begin y axis at the far left almost to end of the right side of the whiteboard. 4. The X axis will be Time without units, and the Y axis North/South without units. N Time S Jobs: Marker Person 1. One person acts a marker person… you sit facing north with marker in hand. 2. Your job is to move the marker north or south at the same rate as Mr. Pearson moves north or south, -also to stop/pause when I do. 3. DO NOT move the marker left or right 4. At the start the marker is place a zero time wherever the teacher is standing on the north south line. Jobs: Time Puller 1. Another person is the “Time Puller”: This person stands at the – East side of the table (left as facing North) 2. Place the white board at arm’s length toward the middle of the table, with just finger tips on it to get ready to pull toward them. 3. When the graphing time starts- the Time Puller pulls board toward them. 4. As the teacher counts down and begins to move the time puller slowly pulls the whiteboard toward them (east) at steady rate. 5. DO NOT stop or slow down or speed up. Let’s DO some graphing! I will call out what I am doing at each step. Position-Time graphs with Displacement • The distance traveled by an object in a period of time often is expressed using a line graph. A line graph visually conveys info using sets of data Directions: 1. Make a graph, use graph paper. Label X-axis, Time (s) and Y-axis, Position (m) & 2. Mark the following data points: (0,0), (2,25), (4, 50), (6,100), (8,180), and (10, 200) 3. With a straight edge, connect the lines 4. Describe the motion shown on the graph 5. What’s the distance traveled? Displacement? 6. Calculate the speed. 25 WHOT Q Draw a position and time graph for a ball being thrown straight up in the air, and coming back down Think of your frame of reference… Force and Motion 2/5 Weekly Highlander Sheet Objective: Analyze position graphs to match a scenario. Responsibilities: Homework!!! Due Friday!!! Quiz Friday! (Side note, no one has come in to retake their quiz from last week…) Warm up What is distance? What is displacement? 3m 3m Start 3m End Motion Graph • Draw a graph (on graph paper) • Label X-axis time (s) & Y-axis position (m) • Graph the following coordinates – (0,5), (5,10), (15,10), (20,10), (25, 25), (30,15) Questions 1) Describe the motion 2) Find the speed between 0-5s and 15-20s 3) What’s the distance traveled? 4) What’s the displacement? 5) Between what times was the motion the fastest? 30 Interpreting Graphs WHOT Q Write a story (like one you just read) about yesterday’s WHOT Q graph Warm Up A halfback (m = 60 kg), a tight end (m = 90 kg), and a lineman (m = 120 kg) are running down the football field. Consider their ticker tape patterns below. Compare the velocities of these three players. How many times greater are the velocity of the halfback and the velocity of the tight end than the velocity of the lineman? Instantaneous or average? https://www.youtube.com/watch?v=pfTTHx9kCHk Dimensional Analysis How do I figure out how much…? How much force do I exert on the floorand inevitably the Earth? Weight = 124 lbs Step 1 Step 2 124lbs 1N .225lb Step 3 = 1lb = 4.45 N 1N = .225 lb 1kg = 2.20 lb 1lb = .454kg X what is in same line …then ÷ Dimensional Analysis How do I figure out how much…? What is the mass of a 40 N cat? Step 1 40N Step 2 .225lb Step 2 1N 1lb = 4.45 N 1N = .225 lb 1kg = 2.20 lb 1lb = .454kg Step 3 Step 4 X what is on top .454kg = ÷ what is on bottom Step 3 1lb Dimensional Analysis How much force do I exert on the floorand inevitably the Earth? ….Let’s just say I weigh 124 lbs Ben Tooclose is being chased through the woods by a bull moose which he was attempting to photograph. The enormous mass of the bull moose is extremely intimidating. Yet, if Ben makes a zigzag pattern through the woods, he swill be able to use the large mass of the moose to his own advantage. Explain this in terms of inertia and Newton’s first law of motion. You are traveling in space and are working outside of your spaceship making repairs. You accidentally throw your wrench. What happens to the wrench? Why is this different from what would happen on earth? You have just been to the grocery store and have several paper bags full of groceries standing in the back of your van. You have to make a sudden stop. What happens to the groceries and why? Warm Up --interpretation of velocity : time graph Describe a story that would be represented by this motion Force diagrams (see attached presentation pages) Read first section of Hewitt reading out loud Concept of net force ID forces on a book sitting on a table Discuss normal force Use pillow and foam as props to show visible upward forces Forces are measured in Newton’s-demo spring scale ID forces on hanging object Use bungees and string as props to show visible upward forces nd Newton’s 2 Law Unbalanced forces cause change in motion Diagrams of balanced and unbalanced forces and resulting motion If time, weight vs mass Give examples for homework from Hewitt on equilibrium Warm Up: Can you solve this math problem? Use the Pythagorean Theorem a2 +b2 = c2 How does this apply to Physics? How far from the start is Anna? In the Vector Addition Lab, Anna starts at the classroom door and walks: 2.0 meters, West 12.0 meters, North 31.0 meters, West 8.0 meters, South 3.0 meters, East What is Anna’s distance? What is her displacement? How far from the start is Anna? WORK THIS PROBLEM… In a grocery store, a shopper walks 36.7 feet down an aisle. She then turns left and walks 17.0 feet straight ahead. Finally, she turns right and walks 8.2 feet to a final destination. (a) Determine the magnitude of the overall displacement. Optional (b) Determine the direction of the displacement vector relative to the original line of motion A student drives his car 6.0 km, North before making a right hand turn and driving 6.0 km to the East. Finally, the student makes a left hand turn and travels another 2.0 km to the north. What is the magnitude of the overall displacement of the student? Vector quantityMagnitude and direction Mac and Tosh are doing the Vector Walk Lab. Starting at the door of their physics classroom, they walk 2.0 meters, south. They make a right hand turn and walk 16.0 meters, west. They turn right again and walk 24.0 meters, north. They then turn left and walk 36.0 meters, west. What is the magnitude of their overall displacement? Vector quantityMagnitude and direction