1. Motion & Forces
Amusement Park Forces

2. What is a Force?
FORCE = Any push or pull which causes something to move or change its speed or direction

5. Balanced Force
30N
30N
The net force on an object is zero and the object’s motion does not change.
Image: Definition:

7. Unbalanced Force
50N
20N
The net force of an object does not equal zero which results in a change in the motion of the object.
Image: Definition:

8. What is a Force?
Forces can be BALANCED or UNBALANCED
Balanced forces are equal in size and opposite in direction
unbalanced forces are not equal in size and/or opposite in direction. If the forces on an object are UNBALANCED, we say a NET force results.
Amusement Park Forces

9. What is a Force? Balanced Forces? Unbalanced Forces?
Can you think of examples of forces?
Balanced Forces?
Unbalanced Forces?

11. Net Force
The sum of all the forces acting on an object. (same direction=add, opposite directions= subtract)
Image: Definition:

14. What is Motion?
Motion: A change in position of an object compared to a reference point
Motion involves all of the following:

15. Forces affect Motion: They can make objects start moving.
They can make objects move faster.
They can make objects move slower.
They can make objects stop moving.
They can make objects change direction.
They can make objects change shape.

17. Gravity is a Force GRAVITY: An attraction force between all masses
Newton’s universal law of gravitation: Every object in the universe exerts a gravitational attraction to all other objects in the universe
The amount of gravitational force depends upon the mass of the objects and the distance between the objects

19. What is Friction?
What are some ways athletes uses friction?

20. Friction is a Resistance Force
Friction = A force that opposes or slows down motion
Caused by the physical contact between moving surfaces
The amount of friction depends upon the kinds of surfaces and the force pressing the surfaces together
Changes motion into heat

21. The rate of change in position
What is Motion?
Speed
The rate of change in position
Speed = distance ÷ time or
= distance
time

22. Velocity What is Motion? Speed plus direction
Example: 50 km/hour north

24. Acceleration What is Motion? The rate of change in velocity
Positive acceleration = speeding up
Negative acceleration = slowing down (decelerate)
A change in the speed rate and/or direction, (velocity), of an object over time.

25. Acceleration by Brainpop
) What units are used to measure speed?
) What units are used to measure acceleration?
) What is another way to say “slowing down” in terms of acceleration?
What units are used to measure velocity?

27. Newton's Laws of Motion

28. Newton's Laws of Motion
First Law(Law of Inertia): An object at rest stays at rest or an object in motion, stays in motion (in the same direction/at the same speed) unless acted upon by an unbalanced force

29. The tendency of an object to resist any change in its motion
Inertia
The tendency of an object to resist any change in its motion
The greater the mass the greater the inertia
The greater the speed the greater the inertia

30. Examples of Newton’s 1st Law (do not copy)
a) car suddenly stops and you strain against the seat belt
b) when riding a horse, the horse suddenly stops and you fly over its head
c) the magician pulls the tablecloth out from under a table full of dishes
d) the difficulty of pushing a dead car
e) lawn bowling on a cut and rolled lawn verses an uncut lawn
f) car turns left and you appear to slide to the right

31. Examples of Newton’s 1st Law of IInertia

32. Newton's Laws of Motion Second law (Law of Force and Acceleration):
The greater the force, the greater the acceleration
The greater the mass, the greater the force needed for the same acceleration
Calculated by: F = ma
(F = force, m = mass, a = acceleration)

33. Examples of Newton’s 2nd Law of Force and Acceleration (do not copy)
a) hitting a baseball, the harder the hit, the faster the ball goes
b) accelerating or decelerating a car
c) The positioning of football players - massive players on the line with lighter (faster to accelerate) players in the backfield
d) a loaded versus an unloaded truck

34. Examples of Newton’s 2nd Law

35. Newton's Laws of Motion
Third law (Law of Action-Reaction): For every action force, there is an equal and opposite reaction force. (Forces are always paired)

36. Examples of Newton’s 3rd Law (Do not copy)
rockets leaving earth
guns being fired
c) two cars hit head on
d) jumping out of a boat onto the dock

38. Examples of Newton’s 3rd Law