1.6 Combing Forces

• What must be known about forces acting on an object?

  Both size and direction
• Why is it important to know the direction of forces?

  To determine the object's acceleration
• What is the resultant force?

  The overall force acting on an object
• What do you need to calculate the resultant force?

  The size and direction of all forces
• What type of quantity is force?

  Vector quantity
• What defines vector quantities?

  They have both size and direction
• Name two examples of vector quantities.

  Force and velocity
• What are scalar quantities?

  Quantities with only size, no direction
• Give two examples of scalar quantities.

  Mass and temperature
• How do you calculate the resultant force when combining vectors?

  Add forces in one direction, subtract in another
• What is the resultant force of a 220 N force north and a 180 N force south?

  40 N north
• What is the resultant force of a 220 N force north, a 180 N force south, and a 90 N force south?

  50 N south
• What is the resultant force acting on a plane with 22,000 N thrust east and 8,000 N friction west?

  14,000 N east
• How do you find the acceleration of an object using F = ma?

  Rearrange to a = F/m
• What is the acceleration of a plane with a resultant force of 14,000 N and mass of 10,000 kg?

  1.4 m/s²
• What is the method to combine vectors?

  Draw vectors end to end
• Why can't you mix different kinds of vectors when combining them?

  They represent different physical quantities
• What are the steps to calculate the resultant force from multiple forces?

  1. Identify all forces acting on the object.
  2. Choose a positive direction.
  3. Add forces in the positive direction.
  4. Subtract forces in the opposite direction.
  5. Calculate the resultant force.
• What are the key characteristics of vector and scalar quantities?

  • Vector quantities:
  • Have size and direction
  • Examples: force, velocity, acceleration
  • Scalar quantities:
  • Have only size, no direction
  • Examples: mass, temperature, time
• How do you calculate acceleration from force and mass?

  • Use the formula:

  $a =$$\frac{F}{m}$

  • Where:
  • $F$ = resultant force
  • $m$ = mass