Forces and their Interactions

• What is a scalar quantity?

  • A quantity that only has a magnitude

  • A quantity that isn’t direction dependent
• What is a vector quantity?

  A quantity that has both a magnitude and an associated direction
• How can a vector quantity be drawn and what does it show?

  • As an arrow

  • The length of the arrow represents the magnitude

  • The arrow points in the associated direction
• What is a force?

  A push or pull acting on an object due to an interaction with another object.
• What are the two categories that all forces can be split into?

  1. Contact forces (objects touching)
  2. Non-contact forces (objects separated)
• Give 3 examples of contact forces

  1. Friction
  2. Air Resistance
  3. Tension
• Give 3 examples of non-contact forces

  1. Gravitational forces
  2. Electrostatic forces
  3. Magnetic forces
• Is force a vector or a scalar quantity?

  • Vector

  • It has both magnitude and direction
• Give 3 examples of vector quantities

  1. Velocity
  2. Displacement
  3. Force
• Give examples of scalar quantities

  • Temperature

  • Time

  • Mass

  • Speed

  • Distance

  • Energy
• What is weight?


  The force that acts on an object due to gravity and the objects mass
• What quantities does weight depend on?

  • The objects mass

  • The gravitational field strenghth at the given postion in the field
• What is the unit used for weight?

  Newtons (N)
• What is the unit for gravitational field strenth?

  N/kg
• What is meant by an objects centre of mass?


  The single point where an objects weight can be considered to act through.
• What piece of equipment can be used to measure an objects weight?

  A calibrated spring-balance or newtonmeter
• What is the name given to the single force that is equilalent to all the other forces acting on a given object?

  The Resultant Force