Vectors

Scalar Quantities

• Physical quantity that has magnitude only

  • Mass, length, time, volume, temperature, pressure, speed

Vector Quantities

• Physical quantity that has both a magnitude and direction

  • position, velocity, force, movement

What is a Force?

• Pushing or pulling interaction of objects

• A vector quantity is defined by its known magnitude and direction

• Point of application of a vector is important

Force Units

• British System of Units

  • pound-force (lbf)

• International System of Units

  • newton (N)

Conversion Between Unit Systems

• 1 lbf = 4.448 N

• 1 N =

Static Equilibrium Force Principles

• Always occurs in pairs acting on two different objects

• Act in opposite directions and have the same magnitude

Resultant Force

• Single force that has the same effect as two or more concurrent forces

Force Components

• A single force can be replaced by component forces if their combination produces the same effect as the original force.

Trigonometric Functions

• sinθ = opposite / hypotenuse

• cosθ = adjacent / hypotenuse

• tanθ = opposite / adjacent