Edexcel AS Physics

Revision Notes

2.4 Scalars & Vectors

Test Yourself

Scalars & Vectors

  • A scalar is a quantity which only has a magnitude (size)
  • A vector is a quantity which has both a magnitude and a direction
  • For example, if a person goes on a hike in the woods to a location which is a couple of miles from their starting point
    • As the crow flies, their displacement will only be a few miles but the distance they walked will be much longer

 

Displacement v distance, downloadable AS & A Level Physics revision notes

Displacement is a vector while distance is a scalar quantity

  • Distance is a scalar quantity because it describes how an object has travelled overall, but not the direction it has travelled in
  • Displacement is a vector quantity because it describes how far an object is from where it started and in what direction

  • Some common scalar and vector quantities are shown in the table below:

Scalars and Vectors Table

Scalars and Vectors Table, downloadable AS & A Level Physics revision notes

Vector Notation

2-4-resolving-vectors-notation_edexcel-al-physics-rn

The arrow on vector notation does not indicate an actual direction, just that the quantity has a direction

  • This means writing the quantity to make it clear that it is a vector
  • In text books vectors are often shown as bold and italic, for example F or s
  • Another form of notation, and easier to do in handwriting, is putting an arrow over the top of the quantity, for example F with rightwards arrow on top or s with rightwards arrow on top
    • The arrow does not indicate the actual direction of the vector, only that is has a direction

Exam Tip

Do you have trouble figuring out if a quantity is a vector or a scalar? Just think - can this quantity have a minus sign? For example - can you have negative energy? No. Can you have negative displacement? Yes!

You've read 0 of your 0 free revision notes

Get unlimited access

to absolutely everything:

  • Downloadable PDFs
  • Unlimited Revision Notes
  • Topic Questions
  • Past Papers
  • Model Answers
  • Videos (Maths and Science)

Join the 80,663 Students that ❤️ Save My Exams

the (exam) results speak for themselves:

Did this page help you?

Lindsay Gilmour

Author: Lindsay Gilmour

Lindsay graduated with First Class Honours from the University of Greenwich and earned her Science Communication MSc at Imperial College London. Now with many years’ experience as a Head of Physics and Examiner for A Level and IGCSE Physics (and Biology!), her love of communicating, educating and Physics has brought her to Save My Exams where she hopes to help as many students as possible on their next steps.