Linear Motion

Linear Motion

Linear motion is the movement of an object along a straight line.

Distance

The distance traveled by an object is the total length that is traveled by that object.

Unit: metre (m)

Type of Quantity: Scalar quantity

Displacement

Displacement of an object from a point of reference, O is the shortest distance of the object from point O in a specific direction.

Unit: metre (m)

Type of Quantity: Vector quantity

Distance vs Displacement

Distance travelled = 200m
Displacement = 120 m, in the direction of Northeast

Distance is a scalar quantity,
Displacement is a vector quantity

Speed

Speed is the rate of change in distance.

Formula:

Unit: ms^-1

Type of quantity: Scalar quantity

Velocity

Velocity is the rate of change in displacement.

Formula:

Unit: ms^-1

Type of quantity: Vector quantity

Acceleration

Acceleration is the rate of velocity change.Acceleration is a vector quantity

Formula:

Unit: ms^-2

Type of quantity: Vector quantity

Notes - Acceleration

• An object moves with a constant velocity if the magnitude and direction of the motion is always constant.
• An object experiences changes in velocity if
  • the magnitude of velocity changes
  • the direction of the motion changes.
• An object that experiences changes in velocity is said to have acceleration.
• An object traveling with a constant acceleration, a, if the velocity changes at a constant rate.

4 Equations of Uniform Acceleration

The above equation is for solving numerical problems involving uniform acceleration.

Summary