Jun 18, 2024

**Motion:**Refers to the change in position of a body with respect to time.**Rest and Motion:**Relative concepts; whether a body is at rest or in motion depends on the reference point.**Example:**A bus driver and a passenger inside the busтАФa static observer sees both in motion, but they appear stationary relative to each other.

**Distance: (Scalar Quantity)**Total path length covered by a body without considering direction.**Displacement: (Vector Quantity)**Straight-line distance between initial and final positions, with direction.**Illustration:**Walking different paths (route1, route2) between points A and B but displacement remains same if start and end points are same.

**Speed:**Distance covered per unit time; scalar quantity. Formula:`Speed = Distance / Time`

.**Velocity:**Displacement per unit time; vector quantity. Formula:`Velocity = Displacement / Time`

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**Instantaneous Velocity:**Velocity at a particular instant of time.**Average Velocity:**Total displacement divided by total time.**Uniform Velocity:**Velocity remains constant over time.**Non-uniform Velocity:**Velocity varies over time.

**Definition:**Rate of change of velocity with respect to time. Formula:`Acceleration = ╬Фv / ╬Фt`

.**Positive Acceleration:**Increase in velocity.**Negative Acceleration (Deceleration):**Decrease in velocity.**Constant Acceleration:**Acceleration is constant over time.**Variable Acceleration:**Acceleration changes over time.

`v = u + at`

`s = ut + 0.5*at┬▓`

`v┬▓ = u┬▓ + 2as`

**Applications:**Solve for unknown variables (initial velocity, final velocity, distance covered, acceleration) using the equations.

- A body remains at rest or in uniform motion unless acted upon by an external force.
**Inertia:**Resistance of a body to change its state of motion or rest.

- Force is equal to the rate of change of momentum. Formula:
`F = ma`

where`F`

is force,`m`

is mass,`a`

is acceleration. **Momentum:**Product of mass and velocity, a vector quantity. Formula:`p = mv`

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- For every action, there is an equal and opposite reaction.
**Example:**Kicking a ball; the ball exerts an equal and opposite force back.

**Elastic Collisions:**Both momentum and kinetic energy are conserved.**Inelastic Collisions:**Momentum is conserved, but kinetic energy is not.

- When a body falls through a viscous liquid, it eventually reaches a constant speed where the force of gravity is balanced by the viscous drag.
**Formula:**`Terminal Velocity тИЭ radius┬▓`

- Used to elevate heavy objects with less force.
**Components of Weight:**Parallel and perpendicular to the inclined plane.**Trigonometric Relations:**`mg sin ╬╕`

and`mg cos ╬╕`

used to resolve forces.**Acceleration on Incline:**`a = g(sin ╬╕ тИТ ╬╝ cos ╬╕)`

where`╬╝`

is the coefficient of friction.

- Worked examples for understanding concepts related to forces acting on bodies, inclined planes, tension, and acceleration.

- Practice problems from various past papers and end-of-chapter questions to reinforce understanding and application of concepts.