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Mahi Tuatahi: Draw a diagram indicating all the forces acting upon you

Drawing Force Diagrams

Muscle Contraction & Light-Headedness


Pātai: Vector Reminder

On your whiteboards, add these vectors (head to tail) to find the resultant (net) force acting.

Pātai: Acceleration

For each, calculate the acceleration that a $5kg$ object would experience.


A state of zero acceleration (constant velocity) due to $F_{net} = 0$.

Recall: Newton’s Second Law

Force is equal to the change in momentum per change in time. For a constant mass, force equals mass times acceleration. $F=m \times a$

TLDR: The acceleration created by a force depends directly upon the mass of the object.


Pātai: Terminal Velocity


  1. What is my net force?

  2. What is my acceleration?

  3. Why does it not equal $g$?

  4. What is my drag and weight forces were balanced?



  1. What is my net force?
    $620N$ down
  2. What is my acceleration?
    $F=ma, a=\frac{F}{m}=\frac{620}{72}=8.61ms^{-2}$
  3. Why does it not equal $g$?
    Because friction is acting against the weight force!
  4. What if my drag and weight forces were balanced?
    $F_{net}=0$ and therefore $a=0$ and I would be in equilibrium.

Akoranga 22 Mahi Tuatahi


Ngā Whāinga Ako

  1. Be able to label different forces
  2. Be able to label forces on an angle

Write the date and ngā whāinga ako in your book


Support/Normal Force

Draw equal and opposite weight and normal forces on your diagram.


Support/Normal Forces on an Angle

Calculating a Missing Force


Worksheet - everything up to but not including the Work section.

Case Study

Step 1. Consider what we know about the motion of the object, and what this implies about the net force acting upon the object.

Question 1

Question 1 Whakatika

Question 2

Question 2 Whakatika

Question 3

Question 3 Continued

Question 3 Whakatika

Question 3 Whakatika Continued

Practise / Whakawai