Analysing linear Motion

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Malaysia SPM Form 4, Chapter 2: Force and Motion
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Contents 1 Mind Map 2 Introduction 3 Distance and Displacement 4 Speed and Velocity 5 Acceleration 5.1 Equaitons for Uniform Acceleration 6 Frequently Asked Question 7 Additional notes 8 External Links

[edit] Mind Map

[edit] Introduction

• Kinematics is the research regarding the types of movement of an object without referring to the forces that cause the movement of the object.
• Movement along a straight line is called linear movement.

[edit] Distance and Displacement

	Distance	Displacement
Definition	The distance traveled by an object is the total length that is traveled by that object.	Displacement of an object from a point of reference, O is the shortest distance of the object from point O in a specific direction.
SI unit	meter (m)	meter (m)
Quantity	Scalar	Vector

Example 1

Distance In the diagram above, the distance of point B from the origin O is 100m. The distance of point A from the origin O is also 100m. Distance is a scalar quantity. Therefore we don't need to tell the direction of point A and B from the reference point, O.

Displacement
In the diagram above, the displacement of point B from the origin O is +100m, whereas the displacement of point A from the origin O is -100m. The + and – sign show the direction of the displacement. Displacement is a vector quantity. Therefore we need to tell the direction of point A and B from O.

Example 2

Adli go to work by motorcycle everyday as shown in the diagram above. The distance traveled by an object is the total length that is traveled by that object. The distance that Adli travels from his house to the factory is 200m. Displacement of an object from a point of reference, O is the shortest distance of the object from point O in a specific direction. The displacement of Adli from his house after arriving at the factory is 120m.

[edit] Speed and Velocity

Speed

• Speed is the rate of change in distance. In other words, it is how fast the distance change in 1 unit of time.
• In mathematics, displacement can be calculated from the following formula:

• Unit: ms^-1
• Type of quantity: Scalar quantity

Velocity

• Velocity is the rate of change in displacement. It is how fast the displacement change in 1 unit of time.
• Formula:

• Unit: ms^-1

• Type of quantity: Vector quantity

[edit] Acceleration

Acceleration

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

• Formula:
  

• Unit: ms^-2
• Type of quantity: Vector quantity

• 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.

[edit] Equaitons for Uniform Acceleration

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

Summary of the Equation

Negative acceleration not necessary mean deceleration! Sometime, it mean the object moving in the opposite direction.

Definition

Distance Distance is defined as the total path traveled by an object from one point to the other. Displacement Displacement is defined as the shortest distance between two point in a specific direction. Speed Speed is defined as the rate of change of distance. Velocity Velocity is defined as the rate of change of displacement. Acceleration Acceleration is defined as the rate of change of velocity. Deceleration Deceleration is the rate of decrease of velocity or how fast a velocity of a moving object decreases.

[edit] Frequently Asked Question

[edit] Additional notes

[Additional notes content information relates to this topic but may not be in the SPM syllabus]

[edit] External Links

Batesville Physchem PhysicsPhenomena FSU Frognet Physchem Interactive Animation Upscale (Flash Video) NTNU (Java Applet) NTNU (Java Applet)