1. Force – Motion

2. Arm Wrestling Competition
A:\Force and Motion\6th 2011\Over the Top - Final Arm wrestle - YouTube.mht

3. Discuss with a partner how you
would describe FORCE.
Name 3 things that describe force

4. A push or a pull on an object.
FORCE
A push or a pull on an object.

5. How could you describe the force being put on the ball?
The picture below shows the water
polo players putting force
on the ball which cause the ball to move.
How could you describe the force
being put on the ball?

6. Force can be described by:
Strength,
Direction
And
Push or Pull

7. Both people are pushing hard. Why isn’t the file cabinet moving?
Quit pushing
I want this in
my office!!!
No way!!
This is going
In my office!
Both people are pushing hard. Why isn’t the file cabinet moving?

8. Balanced Forces Forces are measured in NEWTONS
Balanced forces do not cause a change in motion.

9. Tug a War
7 N

10. Unbalanced Forces Unalanced forces cause a change in motion.
What do you predict is going to happen to the file cabinet?
Unalanced forces cause a change in motion.

11. Tug a War
Yeah baby I won!!
9 N
7 N

12. A net force can also be defined as the overall force acting on
an object, when all the individual forces acting on the object are
added together.
2. Overall power/energy/physical strength
Net Force
7 N
5 N =
7 N
5 N
2 N
To find the net force – subtract the opposing sides
7 N
5 N
7 N
5 N =
12 N

13. 7 N
5 N
9 N
12 – 9 = 3N
7 N
5 N =
9 N
3 N

14. Two dogs are pulling on opposite ends of a rope
Two dogs are pulling on opposite ends of a rope. The dog on the left is pulling with a force of 25newtons. The dog on the right is pulling with a force of 60 newtons. What will be the resulting motion?
A The dogs will not move.
B The dogs will move toward the left.
C The dogs will move toward the right.
D Both dogs will move in the direction that they are pulling.

15. If the forces are acting on the same side of the object, you _____ the numbers
Add
10N
50N

16. If the forces are acting on the opposite sides of the object, you ________ the numbers
Subtract
35N
10N

17. Right
1. Which direction will the box move – left or right? _______ 2. What amount of force will move the box? _____
29 N
55N
26N

18. Which direction will the car move?
Right due to more force applied

19. = 90N
1. What is the total force being applied to the left side of the box? ___ 2. What is the total force being applied to the right side of the box? ___ 3. Which direction will the box move? _____ 4. What amount of force will move the file cabinet? _____
80N
Right
15N
90 – 80 = 10N
80N
75N