PHYSICS: Forces

• What are the two categories of physical quantities measured by scientists?

  Scalars and vectors
• How are scalar and vector quantities treated in calculations?

  They are treated differently
• What is a scalar quantity?

  A physical quantity that has only magnitude
• What does the term 'magnitude' refer to in the context of scalar quantities?

  The size of a physical quantity
• What are some examples of scalar quantities?

  • Temperature (e.g., 10 degrees Celsius)
  • Mass (e.g., 5 kilograms)
  • Energy (e.g., 2,000 joules)
  • Distance (e.g., 19 metres)
  • Speed (e.g., 8 metres per second)
  • Density (e.g., 1,500 kg/m³)
• How can scalar quantities be added together?

  By adding their values together
• If a climber weighs 75 kg and carries a 15 kg backpack, what is their total mass?

  90 kg
• How can scalar quantities be subtracted?

  By subtracting one value from another
• If a room's temperature increases from 12°C to 21°C, what is the increase in temperature?

  9°C
• What are the steps involved in calculations with scalar quantities?

  1. Adding scalars: Sum their values.
  2. Subtracting scalars: Subtract one value from another.
• What is the significance of scalar quantities in scientific measurements?

  • They provide essential data for calculations.
  • They are fundamental in understanding physical phenomena.
• What are the two categories of physical quantities measured by scientists?

  Scalars and vectors
• How are scalar and vector quantities treated differently in calculations?

  Vector quantities include direction, while scalar quantities do not
• What are some examples of vector quantities?

  • Force (e.g., 20 newtons (N) to the left)
  • Displacement (e.g., 50 kilometres (km) east)
  • Velocity (e.g., 11 metres per second (m/s) upwards)
  • Acceleration (e.g., 9.8 metres per second squared (m/s²) downwards)
  • Momentum (e.g., 250 kilogram metres per second (kg m/s) south west)
• What does the direction of a vector represent?

  The direction of a vector indicates where the quantity is pointing
• How can the magnitude of a vector be visually represented?

  By the length of an arrow in a diagram
• What is the significance of the length of an arrow in vector diagrams?

  • Represents the magnitude of the vector quantity
  • Longer arrows indicate larger magnitudes
  • Shorter arrows indicate smaller magnitudes
• What is the example of force given in the study material?

  20 newtons (N) to the left
• What is the example of displacement given in the study material?

  50 kilometres (km) east
• What is the example of velocity given in the study material?

  11 metres per second (m/s) upwards
• What is the example of acceleration given in the study material?

  1. 8 metres per second squared (m/s²) downwards
• What is the example of momentum given in the study material?

  250 kilogram metres per second (kg m/s) south west
• How can the direction of a vector be expressed?

  In a written description or drawn as an arrow
• What are the two categories of physical quantities measured by scientists?

  Scalars and vectors
• What are the key differences between scalar and vector quantities?

  • Scalars: Only have magnitude (e.g., temperature, mass)
  • Vectors: Have both magnitude and direction (e.g., velocity, force)
  • Scalars are simpler in calculations compared to vectors
• How are scalar and vector quantities treated in calculations?

  They are treated differently
• What is a resultant force?

  • A single force that replaces all forces acting on an object
  • Found by adding the individual forces together
  • If balanced, the resultant force is zero
• How do you calculate the resultant force of two forces acting in the same direction?

  Add the magnitudes of the two forces together
• If two forces of 3 N and 2 N act to the right, what is the resultant force?

  5 N to the right
• What is the resultant force when a force of 5 N acts to the right and a force of 3 N acts to the left?

  2 N to the right
• What do free body diagrams represent?

  • Situations where several forces act on an object
  • Visual representation of forces
• What are vector diagrams used for?

  • To resolve (break down) a single force
  • To show two forces acting at right angles to each other
• What is the purpose of vector diagrams?

  To resolve a single force into two forces acting at right angles
• What is the effect of two forces acting in opposite directions?

  They produce a resultant force smaller than either individual force
• How do you find the resultant force when two forces act in opposite directions?

  Subtract the magnitude of the smaller force from the larger force
• What happens to the resultant force if all forces acting on an object are balanced?

  The resultant force is zero
• What is the unit of force used in the examples?

  Newtons (N)
• What is the significance of the resultant force in physics?

  It determines the overall effect of multiple forces acting on an object
• What are the two categories of forces mentioned in the study material?

  Contact forces and non-contact forces
• What is a contact force?

  A force exerted between two objects when they are touching