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?

  • Contact forces (objects touching)
  • Non-contact forces (objects separated)
• Give three examples of contact forces.

  • Friction
  • Air resistance
  • Tension
• Give three examples of non-contact forces.

  • Gravitational forces
  • Electrostatic forces
  • Magnetic forces
• Is force a vector or a scalar quantity?

  ● Vector

  ● It has both a magnitude and an

  associated direction
• Give three examples of vector quantities.

  • Velocity
  • Displacement
  • Force
• Give three 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 object’s mass.
• What quantities does weight depend on?

  Weight = mass x gravitational field strength

  ● The object’s mass

  ● The gravitational field strength at the

  given position in the field
• What is the unit used for weight?

  The Newton (N).
• What is the unit used for gravitational field strength?

  N/kg
• What is meant by an object’s centre of mass?

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

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

  The resultant force.