Skip to main content

Force

Mahi Tuatahi

Brainstorm situations where force is involved, things that cause force and how it can be used in a Physics context on the board!


Force

Force has lots of applications in our world! Everything from cars, to aeroplanes, tug-of-war, sports and even bio-mechanics!



Defining Force

Force is a push or a pull and is measured in Newtons (N).

Forces have a size (1, 2, 3, 4) and a direction (left, right, up, down, $40^{\circ}$).


How Forces Act

Consider you sitting on your seat. What forces are acting upon you?

Draw a box to represent yourself, with arrows coming out of the box to represent the forces. Make sure to label them!



Force Diagram


Balanced Forces

Think and discuss with the people around you:

Sitting on your chair, are the forces acting on you balanced or unbalanced? How do you know? What does it feel like?


Balanced Forces





Vertical and Horizontal Forces




sciPAD Page 33-35


Force & Weight

\begin{aligned} Force = mass \times acceleration \
F = ma \end{aligned}


Weight vs Mass

MassWeight
Measured in $kgs$Measured in Newtons
Is constantChanges with acceleration/gravity
Cannot be measured directlyCan be measured using a scale


Your Weight


Mahi Tuatahi

Complete the questions on the last page of the worksheet from last period!


Types of Forces


Force Diagrams



Task

  1. sciPAD page 34
  2. sciPAD page 36
  3. Use the QR code at the back to find the answers and mark your work!


Ngā Whāinga Ako

  1. Describe the relationship between mass and acceleration of an object which is acted upon by a given unbalanced force (called net force).
  2. Use the relationship $F = ma$ to calculate the net force, mass or acceleration of an object.
  3. Understand forces acting during terminal velocity

Net Force



Terminal Velocity

Source: http://misswise.weebly.com/terminal-velocity.html


Terminal Velocity

Source: https://hardphysics13.wordpress.com/terminal-velocity/


Task

Question 18 and then Question 17 from the mahi kāinga booklet


Mahi Tuatahi

  1. Do you recall $v=\frac{d}{t}$? calculate the velocity of a cyclist that travels $100m$ in $15s$.
  2. What is the difference between mass and weight?
  3. Calculate the weight of a $1.5kg$ mass on Earth.
  4. After $10s$ a runner has accelerated from rest to $3m/s$

L16: Mahi Kāinga Booklet Q19


Mahi Kāinga Booklet Q20