Forces NotesYour directions will be in red

on each slide.

Write today’s title and objective in your journal:

Title: FORCES NOTES

Objective: Identify and describe the changes in position, direction, and speed of an object when acted upon by unbalanced forces.

Think…

Draw the diagram below in your journal. Write the following questions in your journal and answer them.

1. What would happen if both people pushed in the same direction? Why?2. What happens when the people are pulling in the opposite direction?

Why?

Review: What Is Mass?

Mass is the amount of matter in an object.

We measure mass with a triple beam balance.

The unit of measurement for mass is the gram (g).

What Is Force?

Copy the definition in journal and draw picture.

Force is a push or pull that one object exerts on another. A force has both size and direction.

Fkick

Fgravity

How do we measure Force?

Copy these notes into your journal and draw an example picture of a spring scale• Force is the mass of an object multiplied

by the object’s acceleration. We can calculate force using the formula F=ma

•We use a Spring Scale to measure force.

• The unit of measurement for force is the Newton (N)

Let’s Review! Answer the following questions in your journal:

1. What is mass?

2. What tool do we use to measure mass?

3. What is the unit of measurement for mass?

4. What is weight?

5. What tool do we use to measure weight?

6. What is the unit of measurement for weight?

What are some common forces?

Write the definitions in your journal Gravitational Force (Gravity) – The force of

attraction between objects that is due to their masses. You feel the force of gravity pulling you to Earth when you jump up and down.

Weight - a measure of gravitational force on an object. • We measure weight (force) with a Spring Scale.• Unit = Newton

Write the definition and examples in your journal Friction – a force that opposes motion at a

contact point between two surfaces. •Air resistance is a type of friction• Friction makes objects slow down or stop

moving

Copy in journal

Applied force – a push or pull on an object by a person or another object

Net ForceWrite the definition and draw an example diagram in your journal

Net force is the combined effect of all forces acting on an object.

Balanced Forces

Write the definition and notes in your journal

• Balanced forces are forces acting on an object that are opposite in direction and equal in size• There is no change in

position, direction of motion, or speed of an object when all of the forces are balanced• Balanced forces make an

object sit still or keep moving at a constant speed

Unbalanced forcesWrite the definition and notes in your journal • Unbalanced Forces are opposing forces that are not equal• Unbalanced forces cause change in position, direction of motion and speed of an object• Unbalanced forces make objects speed up, slow down, or change direction

Answer the questions in your journal: 1. What are the different forces acting on the figure

skaters?2. In what directions are the forces acting?

3. Are the forces balanced or unbalanced? How do you know?

Balanced and Unbalanced Forces Module

Test your knowledge! Click on the link below and follow the directions on screen.

http://www.engineeringinteract.org/resources/parkworldplot/flash/concepts/balancedandun.htm