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Motion. Process of a change in position Space and time Linear motion Rectilinear motion Curvilinear motion Angular motion General motion. Distance & Displacement. Distance Measured along the path of motion Scalar quantity Linear displacement Measured in a straight line
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Motion • Process of a change in position • Space and time • Linear motion • Rectilinear motion • Curvilinear motion • Angular motion • General motion
Distance & Displacement • Distance • Measured along the path of motion • Scalar quantity • Linear displacement • Measured in a straight line • Resultant displacement • Vector quantity • Direction of a displacement relates the initial position to the final position • Direction can be left, north, positive, down
Velocity Displacement that occurs during a given period of time The rate of change in location Don’t need to know the path of direction! v = change in position / change in time v = position 2 - position 1 / time 2 - time 1 Speed Distance covered divided by the time taken to cover it speed = distance / change in time Must know the path of direction! Velocity & Speed
Linear Acceleration • The change in velocity occurring over a given time interval a = change in velocity / change in time a = velocity 1 - velocity 2 / change in time Velocity 1 = velocity at one point Velocity 2 = velocity at a later point • Units are m.sec2
Average vs Instantaneous Velocity • Instantaneous velocity • Immediate measurement during initial movement • Tremendous effect on distance to be traveled by the object • Average velocity • Final displacement divided by the total time • Female HS sprinters • Maximum velocities occurred at 23 to 27 meters from the start • Elite track athletes • Maximum velocities occur from 40 to 60 meters • Why?
Kinematic data analysis • Track example • Table 2.1 (pg 58) • Interval times • Table 2.2 (pg 58) • Average speeds
Kinematics of Projectile Motion • Vertical component • Gravity • Gravitational acceleration • Maximum height of object obtained • Figure 2.6 • Horizontal component • Distance the object travels • Air resistance • Clothing, equipment, etc. • Figure 2.7
Projectile • Object that has no external forces acting on it other than gravity. • Newton’s 1st law • Horizontal velocity of a projectile is constant • Horizontal motion is in a straight line
Factors Affecting Projectile Trajectory • Angle of projection • Affects the shape of the projectile’s trajectory or path • Don’t forget air resistance • Projection speed • Determines length or size of a projectile’s trajectory • Table 10-2 combines the effects of projection angle and speed • Relative height of projection • Initial height minus landing height • You can have a negative relative projection height
Optimum Projection Conditions • Each individual sporting event has its keys: • Throwing events • *Speed of projection (more important) • Relative projection height • Shot put release angles for the elite (36 to 37 degrees) • Long jump • *Speed of projection • Angle of projection • Jump angles range from 18 to 27 degrees for the elite • High jump • *Angle of projection • Speed of projection (horizontal velocity affects this) • Take-off angles range from 40 to 48 degrees