Kinematics 1Time 1 Time Unit: second (s) Timing Machines Earliest Device : sand-glass & water clock Simple Pendulum Stop Watch Next Slide Photo

Time 2 Measuring Short Time Intervals Timer scaler Mechanism : Measurement of time by phototransistor (cut-off of light) Structure Kinematics 1 Next Slide Photo

Time 3 Measuring Short Time Intervals Ticker-tape timer Mechanism : vibrates 50 times in 1 second Structure Pattern of dots on paper tape Example Kinematics 1 Next Slide Photo Calculation

Time 4 Measuring Short Time Intervals Stroboscope Mechanism : flashes with a constant frequency Structure Stroboscopic image Example Kinematics 1 Next Slide Photo Calculation

Displacement 1 Scalars and Vectors Scalars Definition : quantities with magnitude only Examples : time, distance & mass Vectors Definition : quantities with magnitude and direction Examples : displacement & force Kinematics 1 Next Slide

Displacement 2 Position (Distance and Displacement) Distance Definition : length of the path Unit : metre (m) Property : scalar Kinematics 1 Next Slide

Displacement 3 Position (Distance and Displacement) Displacement Definition : length of the straight line Unit : metre (m) & direction Property : vector Example Kinematics 1 Next Slide Calculation Diagram

Displacement 4 Comparing Distance and Displacement Addition of Distance (Scalar) Addition of Displacement (Vector) Example Kinematics 1 Next Slide Diagram

END of Kinematics I

Kinematics 1Time 1 Timing Machine (Earliest Device) Sand-glass Click Back to Back to

Timing Machine (Pendulum) Simple PendulumPendulum used in Music Kinematics 1Time 1 Click Back to Back to

Timing Machine (Stop Watch) Mechanical Stop WatchElectronic Stop Watch Kinematics 1Time 1 Click Back to Back to

Timing Machine (Timer Scaler) Kinematics 1Time 2 Click Back to Back to

Timing Machine (Ticker-tape Timer 1) Kinematics 1Time 3 Next Slide

Timing Machine (Ticker-tape Timer 2) Kinematics 1Time 3 Click Back to Back to

Timing Machine (Pattern of dots on paper tape) Slow Motion Fast Motion Kinematics 1Time 3 Click Back to Back to

Timing Machine (Ticker-tape timer) (Example) ABC 3 cm6 cm Time interval between successive dots : 0.02 s (Why?) Time required to travel from A to B = 0.02 × 3 = 0.06 s Time required to travel from B to C = 0.02 × 5 = 0.10 s Time required to travel from A to C = 0.02 × 8 = 0.16 s Kinematics 1Time 3 Click Back to Back to

Timing Machine (Stroboscope 1) Stroboscopic Lamp Kinematics 1Time 4 Next Slide

Timing Machine (Stroboscope 2) Kinematics 1Time 4 Click Back to Back to

Timing Machine (Stroboscopic image) Stroboscopic photograph for the motion of a simple pendulum Kinematics 1Time 4 Click Back to Back to

Timing Machine (Stroboscope) (Examples) Stroboscopic photograph for an object sliding down Frequency : 10 Hz Time required to travel from A to B = 1/10 × 2 = 0.2 s Time required to travel from A to C = 1/10 × 4 = 0.4 s A B C Kinematics 1Time 4 Click Back to Back to

Vector (Representation & Example) Magnitude : Length of Arrow with a scale e.g. 1 cm to 1 m, 2 cm to 1 N Direction : Direction of the Arrow Kinematics 1Displacement 3 Click Back to Back to

Distance & Displacement (Example) 3 m AB 4 m C Someone travels from A to C through B as shown. Total distance traveled: = length of the path = (3 + 4) m = 7 m Total displacement traveled: = straight arrow joining starting point and end point of the path = 5 m (direction : N 36.9°E) North 36.9° Kinematics 1Displacement 3 Click Back to Back to

Addition of Distance and Displacement Addition of Distance : 3 m + 4 m = 7 m Addition of Displacement : Tip to Tail Method Kinematics 1Displacement 4 Click Back to Back to