"Motion" Class IX Presentation.pptx.Topper
- 1. Motion - Class IX Science Chapter in Student-Friendly Language
- 2. What is Motion? • Motion means change in position of an object with time. • If an object is not changing its position, it is at rest. • Example: A moving car or a flying bird is in motion.
- 3. Types of Motion • 1. Linear Motion - in a straight line (e.g. car on road) • 2. Circular Motion - around a circle (e.g. fan blade) • 3. Periodic Motion - repeats in fixed time (e.g. pendulum)
- 4. Distance and Displacement • Distance: Total path covered. Scalar quantity. • Displacement: Shortest path from start to end. Vector quantity. • Example: Walking around a park vs walking straight across it.
- 5. Speed and Velocity • Speed = Distance / Time (no direction) • Velocity = Displacement / Time (has direction) • Both have same units (m/s) but velocity is a vector.
- 6. Acceleration • Acceleration = Change in velocity / Time • Unit: m/s² • Positive acceleration: speed increases • Negative acceleration (retardation): speed decreases
- 7. Distance-Time & Velocity-Time Graphs • Distance-Time Graph: Slope gives speed • Straight line = Uniform speed • Velocity-Time Graph: Slope gives acceleration • Area under graph = Distance travelled
- 8. Equations of Motion • 1. v = u + at • 2. s = ut + 1/2 at² • 3. v² = u² + 2as • Where u = initial velocity, v = final velocity, a = acceleration, t = time, s = distance
- 9. Uniform Circular Motion • An object moving in a circle with constant speed • Velocity changes due to change in direction • Example: Moon revolving around Earth