Motion

Motion

Defining Motion

• Objects are said to be in motion if their position is changing with respect to a reference point.
• An object can be moving even if it appears to be still, depending on the observer’s point of view.

Distance and Displacement

• Distance is a scalar quantity that describes how much ground an object has covered during its motion.
• Displacement is a vector quantity that refers to the object’s overall change in position.

Speed and Velocity

• Speed is the rate at which an object covers distance.
• Speed equals distance divided by time.
• The units of speed are typically metres per second (m/s).
• Velocity is a vector quantity that refers to the speed of an object in a particular direction.

Acceleration

• Acceleration is the rate at which an object changes its velocity.
• Acceleration happens when an object changes its speed, direction, or both.
• It is a vector quantity with units of metres per second squared (m/s²).

Graphical Representation of Motion

• A distance-time graph displays how far an object has travelled against time.
• The gradient on a distance-time graph represents the speed of the object.
• A velocity-time graph plots velocity against time.
• The gradient of a velocity-time graph depicts the acceleration of an object, while the area under the graph represents the distance travelled.

Equations of Motion

• Average speed = Total distance ÷ Total time.
• Acceleration = Change in velocity ÷ Time taken.
• Final velocity = Initial velocity + (acceleration x time).
• Distance = Initial velocity x time + 0.5 x acceleration x time².