The Basics of Motion - Physics Paper 2




  • Speed is a scalar quantity. 

  • Scalar quantities only have a magnitude (size). 

  • Scalar quantities, like speed, do not have a direction. 





  • Velocity describes an object’s direction as well as its speed. 

  • Velocity is a vector quantity because it has a magnitude (or size) and a direction. 


Typical Speeds 


  • Typical walking speed is 1.4m/s. 

  • Typical running speed is 3.3m/s. 

  • Typical speed of a bus in town is 10m/s. 

  • Typical speed of a car on the motorway is 31m/s. 

  • Typical speed of wind is 6m/s. 

  • Typical speed of sound is 340m/s. 


Adding Vectors 

Adding Vectors


  • To add vectors, draw each vector as an arrow one after the other. 

    • The length of the arrow represents the magnitude (size) of a quantity. 

    • The direction of the arrow represents the direction of the vector quantity. 



Vector Addition 


Vector Addition

  • Jane pushes a table with a force of 10N towards the door, but her brother, Frank tries to stop her by pushing it with a force of 10 N at a right angle to Jane. 

  • The effect of these forces is shown above. 

    • Pythagoras’ theorem is used to work out the resultant force. 

    • Resultant Force = √(10


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