DO NOW MONDAY 3/19 -YOU ARE GOING HOME FROM SCHOOL YOU TRAVEL 4 KM, YOU DECIDE TO STOP AT THE MALL WHICH IS ANOTHER 4 KM, THEN YOU GRAB DINNER AT TACO BELL WHICH IS 2 KM AWAY. THE TRIP TAKES YOU 2 HOURS. WHAT IS THE AVERAGE SPEED OF YOUR TRIP? -5 KM/H

AGENDA Do now (2 min) Notes/videos (10 min) Class practice (5 min) Group Practice (8 min) Independent Practice (10 min) Closing (5 min)

REMINDERS: MARBLE LAB REPORT DUE TOMORROW DON’T FORGET YOUR BACKGROUND/INTRO Lose ten points for every day late No ed/flash drive work- Must be printed

TOPIC: FORCES Write in Questions as we go

WHAT IS FORCE? A force is simply a push or a pull. All forces have both direction and strength Any time there is a change in acceleration this means that the change was caused by a force.

WHAT IS A FORCE? All forces act on objects. Not all forces causes an object to move. For example you are all sitting on chairs, this exerts a force, but you do not cause the chair to move by sitting on it. You also cannot see all forces, like the force of gravity or the force that attracts two magnets.

1 MINUTE, WITH A PARNER: TRUE OR FALSE  1. A force is a push or a pull  2. You can see all forces  3. Forces always cause an object to move

NET FORCE  Usually more than one force is acting on an object. the combination of all the forces acting on an object.  The NET FORCE is the combination of all the forces acting on an object.

BALANCED FORCE When the forces of an object produce a net force of 0, then the forces are BALANCED FORCES. Balanced forces will not create a change in motion of an object. Some examples of balanced forces are a hat sitting on your head, a birds nest resting in a tree, or a light bulb hanging from the ceiling

UNBALANCED FORCE  When the net force is ANYTHING other than 0 then the force is UNBALANCED.  For example a tug-a-war between is an unbalanced force.  Unbalanced forces  Unbalanced forces are necessary to move an object.

5 TYPES OF FORCES F f = Friction force F A = Applied Force F n = Normal Force F g = Gravity F air = Air resistance

FRICTION A soccer ball rolling on the grass stops because of friction

exerted by the surface as an object moves across it and opposes the motion

FRICTION On a wet or icy surface, there is less friction, and people slip easily

APPLIED FORCE applied by an object or a person

NORMAL FORCE support force exerted on an object on any surface; always 90 degrees to the horizontal

Normal Force What are the 2 forces acting on you RIGHT NOW? NORMAL FORCE

gravity

Air resistance a type of frictional force that acts on objects moving the air and opposes the motion

Air resistance What two forces are at work on a skydiver?

2 MINUTES: FOLD YOUR NOTES OVER AND QUIZ YOUR PARTNER

CLASS PRACTICE Label the forces that are acting in each situation

A PERSON STANDING ON THE FLOOR.

A WAGON BEING PULLED UPHILL. Fg Fn Fa Ff

A CAR DRIVING DOWN THE STREET.

A PERSON PUSHING A WALL.

A FOOTBALL TOSSED IN THE AIR.

LIBRARY VOICES, 10 MIN, IN GROUPS

1)An airplane flying (3 forces) Fg, Fa, Fair 4) A ball being tossed in the air (3 forces) Fair, Fg, Fa 1)A glass sitting on a table (2 forces) Fn, Fg 1)A ball that was pushed and it rolling across a table (4 forces) Fa, Ff, Fg, Fn 5) A rolling chair shoved and rolling across the floor (4 forces) Fa, Ff, Fg, Fn

INDEPENDENT PRACTICE SILENT, ALONE

CLOSING Is the net force on the pencil sharpener BALANCED or UNBALANCED? How do you know? ANSWER IN TAG OR RECEIVE ZERO POINTS

DO NOW 3/20 In a game of tug of war like the one shown above, are the forces BALANCED or UNBALANCED? Explain your answer.

AGENDA- PLACE YOUR LAB REPORTS DUE TODAY IN ONE PILE ON YOUR TABLE Do now Assign HW Forces practice Independent practice Closing

HOMEWORK DUE FRIDAY

WITH A PARTNER, LIBRARY VOICES, AT YOUR TABLES 20 MIN Complete the tasks on your paper and answer the questions. I will collect one per partner group

INDEPENDENT PRACTICE, 10 MINUTES SILENT, ALONE Page 73

CLOSING What are the forces acting on a ball kicked along a field? Are they balanced or unbalanced? ANSWER IN TAG