1. Use the Force… To discuss what forces can do for them.
A long time ago
In a classroom far, far away,
A group of future scientists gathered
To discuss what forces can do for them.

2. Force is a Vector.
It is drawn as an arrow. The length represents the magnitude. The arrow points in the direction of the vector.

3. Examples of ways to describe forces:
Force is a Vector.
Examples of ways to describe forces:
20 lbs to the right
115 N, 45 degrees south
35 N northeast
10 lbs 30 degrees below the horizontal.

4. Force, F, is a Vector.
The effect a force has on an object depends on the force’s magnitude (size) and it’s direction.

5. Same magnitude, different direction = different force!
Force, F, is a Vector.
Same magnitude, different direction = different force!
Start

6. Net Force Forces In the Same Directions
Sara pulls the wagon with a force of 20 newtons (20 N) to the right. Tom pushes the wagon with a force of 30 newtons (30 N) to the right. What net force acts on the wagon?

7. Net Force Forces In Opposite Directions
Red pushes blue with a force of 75 newtons (75 N) to the right. Blue pushes red with a force of 100 newtons (100 N) to the left. Which direction will the players move?

8. Net Force Forces In Different Directions – analytical solultion
Two people pull on a boat with ropes. They pull at a right angle to each other. The one on the side pulls with 40 N of force. The one at the bow pulls with 30 N of force. Find the net force.

9. Net Force Forces In Different Directions – graphical solution
Draw a scale diagram of the vectors.
1cm = 10 N
Draw vectors “tip to tail”.
Resultant is the vector connecting the start of the first to the end of the last.
Measure the resultant (answer) with a ruler.