0What is Motion?
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Motion is the change in the position of an object with respect to time.
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An object is said to be in motion if it changes its place from one point to another.
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Motion is relative, meaning it is observed with respect to a reference point.
Example: A car moving on a road appears in motion to a person standing on the road, but it appears stationary to a person inside the car.
2. Types of Motion
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Linear Motion
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Motion along a straight line.
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Example: A train moving on a straight track.
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Circular Motion
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Motion along a circular path.
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Example: A Ferris wheel rotating.
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Rotatory Motion
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Motion around its own axis.
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Example: A spinning fan.
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Oscillatory Motion
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Motion that repeats back and forth around a fixed point.
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Example: Swing, pendulum.
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Random Motion
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Motion that does not follow a definite path.
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Example: Movement of dust particles in air.
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3. Terms Related to Motion
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Distance and Displacement
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Distance: Total path covered by an object.
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Displacement: Shortest distance between starting and ending points, direction matters.
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Speed and Velocity
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Speed: How fast an object is moving (no direction needed).
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Velocity: Speed with direction.
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Acceleration
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The rate at which velocity changes.
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Can be positive (speeding up) or negative (slowing down).
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4. Uniform and Non-uniform Motion
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Uniform Motion
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Moves equal distance in equal intervals of time.
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Example: A car moving at constant speed on a straight road.
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Non-uniform Motion
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Moves unequal distances in equal intervals of time.
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Example: A car slowing down near a traffic signal.
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5. Key Points for Class 9
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Motion is relative.
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Types: Linear, Circular, Rotatory, Oscillatory, Random.
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Distance vs Displacement – path vs shortest line.
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Speed vs Velocity – scalar vs vector.
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Uniform vs Non-uniform – constant vs changing motion.
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Motion concepts are used everywhere: vehicles, sports, machinery, and daily life.
