Motion, Acceleration, and Graph Interpretation

Acceleration and Velocity  

- When velocity increases with time, acceleration is positive.  

- When velocity decreases with time, acceleration is negative (also called deceleration).  

- If acceleration is zero, the object moves at a constant velocity.  

Motion Graphs  

Graphs help visualise how an object moves over time.  

- Time is plotted on the x‑axis, and distance or speed on the y‑axis.  

- When the object is at rest, the graph shows a horizontal line (no change in distance).  

- When distance increases uniformly with time, the object moves at a constant speed.  

- When the graph curves upward, it indicates an increase in speed; the object is accelerating.  

Acceleration Values  

- Positive acceleration: Speed increases.  

- Zero acceleration: Speed remains constant.  

- Negative acceleration: Speed decreases (deceleration).  

- In deceleration, the negative acceleration value is often expressed as a positive number to indicate the rate of slowing down.  

Time Period  

- The time period is the time taken to complete one full oscillation or cycle of motion.  

Simple Pendulum Concepts  

- When an object is at rest, its initial velocity = 0 m/s.  

- The maximum displacement of a simple pendulum on either side of its mean position is called its amplitude.  

Insight:  

Motion graphs and acceleration values help describe how objects move, whether steadily, speeding up, or slowing down. In oscillatory motion like a pendulum, these principles explain how energy and displacement vary rhythmically over time.