On your next blank page, take notes

Force Notes

Net Force

• In many situations, including driving, more than one force is acting on an object.

• The combination of all forces acting on an object is the net force.

• Net force determines whether, and by how much, an object’s motion is changed.

• Total Force

Force Diagrams

• Objects are shown as a rectangle or square.

Force Diagrams

• A push or pull (force) is shown with an arrow

Force Diagrams

• The arrow always points AWAY from the object.

Force Diagrams

• The bigger the force, the bigger the arrow

Force Diagrams

• Label the arrows with the magnitude (amount) of the force (in N)

10 N3 N

Force Diagrams

• Net Force is the sum of all of the forces

10 N3 N

7 N

Practice:

• Draw an object with two forces acting in opposite directions with one force equal to 2 N and one force equal to 8 N.

Force Diagrams

8 N2 N

Net Force

• Draw the net force acting on this object.

8 N2 N

Force Diagrams

Net Force

6 N

Balanced vs. Unbalanced Forces• If there is a situation of unbalanced forces,

there is a net force.

• Balanced forces mean there is a net force of zero on the object.

• Describe the motion of the blocks below.

10 N2 N

8 N8 NA.

B.

Read pg. E-37

Activity 81

Title: The Net Force Challenge

Problem: How can you tell if the forces on an object are balanced or unbalanced?

Hypothesis: If _____________, then ______________________________.

Read the procedure on pages E-38 to E-39

Data/Evidence:

Part A: Balanced Forces

Step 3.

Part B: Unbalanced Forces

Step 6.

Step 7.

Etc.

Spring Scale

• BE GENTLE!!!!