BeginnerTopic 18 of 104Engineering Mathematics

Vectors

Quantities with magnitude and direction, such as force and velocity, added tip-to-tail or by components.

In depth

A vector has magnitude and direction and adds by components or tip-to-tail. Unit vectors i, j, k give a basis. Position, velocity, force and fields are vectors. The magnitude is ‖v‖=√(vx²+vy²+vz²).

Key points

  • Scalar multiplication scales length
  • Unit vector = v/‖v‖
  • Components are found with trigonometry
Example

(3,4) has magnitude 5 and direction atan(4/3) ≈ 53°.

Why it matters

Vectors combine magnitude and direction, which is needed for every force, velocity, field and displacement in mechanics and electromagnetism.

Where this is used

  • Summing forces acting on a bracket.
  • Computing the resultant wind load on a tower.
  • Describing the direction of a magnetic field at a sensor.

Frequently asked questions

What is Vectors?

Quantities with magnitude and direction, such as force and velocity, added tip-to-tail or by components.

Why is it important to understand vectors?

Vectors combine magnitude and direction, which is needed for every force, velocity, field and displacement in mechanics and electromagnetism.

How do I add two vectors graphically and numerically?

Add components along each axis for the numerical method. Place them tip to tail for the graphical method, and the resultant runs from the first tail to the last tip.

What is a unit vector?

A vector of length one that points in a direction. Dividing a vector by its magnitude gives its unit vector.

How is Vectors used in practice?

Typical applications include summing forces acting on a bracket, computing the resultant wind load on a tower and describing the direction of a magnetic field at a sensor.

What should I learn before Vectors?

Study "Coordinate geometry" first (topic 17 of 104 in Engineering Mathematics). It covers the groundwork this topic builds on.

What are the key points of Vectors?

Scalar multiplication scales length. Unit vector = v/‖v‖. Components are found with trigonometry.

Can you give an example of Vectors?

(3,4) has magnitude 5 and direction atan(4/3) ≈ 53°.

What comes after Vectors?

The next topic is "Dot product", which builds directly on this one.

How difficult is Vectors?

It is classed as Beginner in Engineering Mathematics (topic 18 of 104). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.

Learning path

Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.

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