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Angular Kinematics Contents of the Lesson Angular Kinematics Contents of the Lesson Angular Motion and Kinematics Angular Distance and Angular Displacement. Angular Speed and Angular Velocity Angular Acceleration Questions. Motion “change in the position of an object with respect to some reference frame.” Planes and Axis. Angular Motion “Rotation of a object around a central imaginary line” Characteristics: ◦ Axis of rotation. ◦ Whole object moves. Identify the angular motion Angular motion in the human body “most of movement are angular” In the human body; ◦ Joint= Axis of rotation. ◦ Body segment= object or rotatory body. ◦ Initial position= anatomical position. Kinematics; Angular Kinematics “Description of Angular Motion” Seeks to answer? “How much something has rotated?” “How fast something is rotating?” etc. Units of measurements Degrees. Radian Units of measurement Revolutions 1 revolution= 1 circle= 360 degrees= 2휋.radians Angular Distance “Sum of all angular changes undergone by a rotatory body” Unit: degrees, radian revolution. Angular Displacement “difference between the initial and final position of a rotatory body around an axis of rotation with regards to direction.” Direction= counter clockwise or clockwise In Human movement= Flexion,Extension,etc. What will be the angular displacement? Angular Speed “Scalar quantity” “angular distance covered divided by time interval over which the motion occurred” Angular Velocity “Vector quantity” “rate of change of angular position or angular displacement w.r.t time” Angular speed and Velocity Angular speed = degree/sec, rad/sec, or revolution/sec. Angular Velocity= degree/sec, rad/sec, or revolution/sec counterclockwise, clockwise or flexion or extension, etc. Angular Acceleration “Rate of change of angular velocity w.r.t time.” Unit= degree/sec² Calculate acceleration. Initial velocity= 0 Final velocity= 80 degree/sec. Time= 3 seconds. Types of Angular Acceleration Angular Acceleration (+) Angular (-) Angular Acceleration Acceleration Types of Angular Acceleration References Hall, S. J. 1. (2004). Basicbiomechanics (Fourth edition.). New York: McGraw-Hill Education. Questions 1. Which branch of dynamics studies the “geometry” of motion? 2. _______ is usually used to measure the angular displacement/distance in the case of rotations of total body in gymnastics,etc. 3. Which of the following is a scalar quantity? a) Angular Speed, b) Angular Velocity c) Angular Acceleration. d) None of the above. Questions 4. What is the basic difference between angular distance and angular displacement? a) Scalar and Vector quantity. b) Part of angular kinematics c) Part of angular motion d) None of the above. 5. If flexion is considered as a (+) direction then _____ is the (-) direction in the angular acceleration calculation. Questions 6. Calculate the angular displacement. Questions 7. Calculate the angular displacement in radians. Questions 8. When angular acceleration= 0; angular velocity is ______? a) 0 b) Increasing c) Decreasing d) Constant 9. If Abduction is considered as (+) direction then _____ is considered as (-) direction in the angular acceleration calculation. Questions 10. What is the unit of Angular acceleration? a) degree/sec. b) degree/sec^3 c) radian/sec² d) revolution/sec. 11. Which among the following is the largest unit of measuring angular distance and displacement: a)Revolution b) Degree c) Radian d) Meters Questions 12. Identify the body segments exhibiting angular motion. Questions 13. Calculate the angular velocity, if the time period = 2 seconds. Questions 14. Which among the following is the smallest unit of measuring angular distance and displacement: a)Revolution b) Degree c) Radian d) all of the above 15. What are the two necessary characterstics of a angular motion? Answer 1. Kinematics 2. Revolutions 3. A) Angular Speed 4. A) Scalar and Vector Quantity 5. Extension 6. + 165 degrees 7. 휋/2 8. D) Constant 9. Adduction 10. C) Radian/sec² Answer 11. A)Revolution 12. Arms and legs or Upper arm, forearms, legs. 13. 45 degree/sec. 14. Degree 15. Axis of Rotation and Whole Body should move. Doubts? .
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