Day 1: Intro to Forces

FQ:  How do we recognize and name forces?

1. Intro to Forces:

When you ride a bike, your foot pushes against the pedal. The push makes the wheels of the bike move.
When you drop something, it is pulled to the ground by gravity.
A PUSH or a PULL is a FORCE. So, a good definition for force is a push or pull in a particular direction.
Forces affect how objects move. They may cause motion; they may also slow, stop, or change the direction of motion of an object that is already moving. 

4 effects of forces:

Forces cause changes in motion.  In other words, they cause acceleration.  This means forces do one of 4 things:
→ Increase object's speed
→ Decrease object's speed

→ They can make objects change direction
→ They can make objects change shape

Naming Forces:
→ Forces are measured in Newtons (N)
→ Forces act in a particular direction, so we represent them with an arrow.
→ Forces sometimes cannot be seen, but their effects can 

When we label forces, we want to indicate what object is giving the force and what object is receiving the force. Therefore, we will use the following notation:

F _{from giver, on receiver}

For example, the gravity force acting on a person would be written

F _{from Earth, on person}

2. Newton's 3 Laws of Motion:

1. Objects keep doing what they're already doing until a net force is applied. 

2. Unbalanced forces cause objects to accelerate. 

3. Every action force has an equal and opposite reaction force.

3. Competition:  Broom Ball!  

Where does the ball speed up?  slow down?  change direction?

5. Optional / Advanced:  Concept Builders 

   Reading:  Types of forces

   Recognizing Forces Concept Builder

   Balanced/Unbalanced Concept Builder