chapter 2

Mechanics: Study of motion.
Kinematics: Study of motion without considering its causes. The term "kinematics" derives from Greek, meaning motion.
Focuses solely on the motion of objects, disregarding the forces causing or changing that motion.

Rest: An object does not change its position over time, e.g., a bench.
Motion: An object changes its position over time, e.g., a moving car.
Relative Nature of Motion: An object can be at rest in one frame of reference while in motion in another.
- Example: A car moving on a spinning Earth.

Translatory Motion: All points move uniformly in the same direction without changing orientation.
- Example: A basketball rolling without spinning.
Rotatory Motion: An object rotates around its axis.
- Example: A basketball spinning on a player’s finger.
Vibratory Motion: An object moves forward and backward repeatedly about a fixed position.
- Example: A swinging pendulum.
Translatory Motion Types:
- Rectilinear Motion: Straight-line motion.
  - Example: A falling apple.
- Curvilinear Motion: Motion along curved paths.
  - Example: A car going around a curve.
- Random Motion: Irregular motion without a specific path.
  - Example: A butterfly flying.

Distance: Length of the path traveled, scalar quantity.
- Example: Walking in Faisal Masjid to Blue Area.
Displacement: Shortest distance between the initial and final position, vector quantity.
Example: Path showing the actual move to Blue Area is shorter than the traveled path.
Notable Concept: Change in position represented by Greek letter "Δ".

Definition: Measure of how fast an object is moving; distance traveled per time.
Speed is a scalar quantity; SI unit: m/s.
Example: Traveling from Tarnol to Sawabi over 70 km in 1 hour gives speed.
Average Speed: Total distance covered over total time.
Instantaneous Speed: Speed at a given moment in time.
- Example: Speedometer reading.
Uniform Speed: Equal distances in equal time periods.
Variable Speed: Changing speeds over time.

Velocity: Rate of change of displacement, vector quantity (direction matters).
SI unit: m/s.
Average Velocity: Total displacement over total time.
Instantaneous Velocity: Velocity at an exact moment.
Uniform and Variable Velocity: Describes consistent or changing displacement over time.

Definition: Measure of change in velocity over time; vector quantity.
SI unit: m/s².
Positive acceleration: Increase in velocity.
Negative acceleration (deceleration): Decrease in velocity.
Uniform Acceleration: Constant change in velocity over time.
Non-uniform Acceleration: Varying changes in velocity; real-life scenarios often involve this concept.

All freely falling objects experience the same acceleration due to gravity, independent of mass.
- Gravitational acceleration (g) ≈ 9.8 m/s² downward.
Objects in free fall accelerate uniformly towards Earth.

Graph plotting distance vs. time.
Slope of the graph indicates speed.
Different scenarios depicted:
- At rest: Constant distance, slope = 0.
- Constant speed: Linear increase in distance.
- Variable speed: Non-linear increase in distance.

Graph plotting speed vs. time.
Slope indicates acceleration, area represents distance traveled.
- Example: Calculating area under graphs for distance.