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Slides 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Displacement Vectors Kinematics Graphs Energy Power Springs Shadows Field of Vision Colors Concave mirrors Convex mirrors Refraction Lenses Optical Power Slides Minutes 9 27 13 39 13 39 10 30 10 30 5 15 4 12 3 9 7 21 3 9 7 21 4 12 5 15 10 30 6 18 Free Body Diagrams A free body diagram is a pictorial representation of an object used to study the forces acting on a system. A free body diagram shows only the information required by the problem under study. Ending point Distance is a scalar. (It has no direction) Displacement is a vector. (It has direction) Starting point Ao Displacement is the straight line directly from the starting point to the ending point. Remember: Displacement has magnitude and direction. Click Displacement Slide: An object travels the following distances: III II 9 m [E], 6 m [N], 4 m [W] and 2 m [S] Which of the vectors on the right represents the displacement of the object? A) B) C) D) I II III IV I IV 4 m [W] 2 m [S] 6 m [N] Displacement 9 m [E] Not drawn to scale Click Displacement Slide: Riding her bike, Stefania traveled the following distance from point-A to point-D: AB = 4.00km North BC = 11.3 km [S 45 E] CD = 8.00 km West Determine Stefania’s displacement. A) 4.00 km North B) 4.00 km South C) 23.3 km North D) 23.3 km South E) 0 Note BD = CD = 8.00 km and BA = AD = 4.00 km Click Displacement Slide: The graph below represents the velocity of a butterfly as it flies across a field for 20 seconds. +235 m (forward) -90 m (backward) What is the displacement of the butterfly from the 4 th to the 20 th s? A) 365 m B) 325 m C) 185 m D) 145 m Displacement Slide: To go from his house to four of his friends, James must travel in different directions as listed below: NOTE Ann: 4.8 km [N] , 3.2 km [W] We need only consider Bill: 20 km [N] , 15 km [S] the magnitude and not Chris: 3 km [N] , 7 km [S 45o E] the direction. Don: 3.5 km [S] , 1 km [E] , 2 km [S] Which friend has the greatest displacement from James’ house? A) Ann Ann: 5.8 km Bill: 5 km B) Bill Chris: 5.4 km C) Chris Don: 2.5 km D) Don Click Displacement Slide: 0 20 km E Displacement is a vector from the starting point directly to the ending point. Click Displacement Slide: 1 2 3 4 5 Click Displacement Slide: Click 2 km Ending point Displacement Slide: Starting point Displacement Slide: The graph below represents the motion of an automobile as it moves northward. Determine the displacement of the automobile. Right represents North Forward Remember: displacement is the straight line from the Displacement starting point to the ending point. The forward velocity displacement is the under the curve above the x-axis Positive (above thearea x-axis) means going forward. NOTE The area fromvelocity the line to the x-axis forward Since plotted The backward displacement is is the area aboverepresents the curve below the x-axis distance since it has versus time, the areaa positive value. Negative to velocity (below the x-axis) means going backward. the x-axis represents Note that represents for the problem, the time The areathe from the linetraveled. to the x-axis backward distance the ending point (t = 20 s). distance since itstops has aat negative value. Forward Backward However, according to the graph, the Ending Starting automobile continues to accelerate point point 160 m North backwards. Click Click … and good luck!