Post on 29-Dec-2015
Chapter 12
Force
Force Vocabulary
FORCE-
BALANCED FORCES-
UNBALANCED FORCES-
A push or pull.
Forces that are equal in size, but opposite in direction.
Forces that cause a change in the motion of an object.
Force VocabularyGRAVITY- Force of attraction between all
objects in the universe.
NEWTON-
WEIGHT-
MASS-
SI unit of force.
The amount of matter in an object.
Measure of the force of gravity acting on an object.
Force VocabularyFRICTION-
STATIC FRICTION-
SLIDING FRICTION-
ROLLING FRICTION-
AIR RESISTANCE-
Force that opposes the motion of an object.
Occurs when objects are not moving.
Occurs when 2 objects slide past each other.
Occurs when 2 objects roll past each other.
An upward push as an object falls.
Force Vocabulary
LUBRICANTS- Materials that reduce friction.
Key Topic is…
What is Force?
Our Objective is…
Define force and give examples of forces in nature.
Identify balanced and unbalanced forces and describe their effects.
1st Main Idea…
Force A ________ is
_________________________. A ______ always
___________________________. If the force is _________ __________,
the object _____ ______ in the ________________________.
Force
? ?
PUSH PULL
Courtesy: Clipart.comCourtesy:tugfest.com
Ch. 12 Force Sec 12-1
2nd Main Idea…
Balanced Forces To _______ a force, you must
________________. 1. 2.
______ forces are _____________________ and ______________________.
_________ forces do not
Examples!!
Balanced Forces-No Movement
25 N 25 N
Courtesy: clipart.com
Force3rd Main Idea…
Unbalanced Forces _________ forces cause
___________________ ____________________.
Ch. 12 Force Sec 12-1
UnBalanced Forces-Movement
25 N 10 N
Courtesy: clipart.com
Force
4th Main Idea…
Forces & Motion ________ forces can ______________
_______________________. 1. 2.
5th Main Idea…
Forces In Nature
Examples of forces you experience everyday:
_________- a measure of _________ between ________________________.
_______ force- attraction of a __________________________________.
_____ force-moving _________________. Falling ______ is caused by
________________.
Force
http://www.milfordroad.co.nz/images/avalanche.jpghttps://www.forcefieldmagnets.com/catalog/images/cat_magnets.jpg
http://www.lcpu.org/images/windy-day.jpg http://www.codinghorror.com/blog/images/waterfall.jpg
Force – Part 2Key Topic is…
What is Gravity?
Our Objective is…
Explain Newton’s
laws of gravity.
Force – Part 21st Main Idea…
Sir Isaac Newton ________ hypothesized that there is a
________ called _________ that makes _______________________________________.
Newton’s law of Universal Gravitation- _________________________________ __________________________________________________________________.
Ch. 12 Force Sec 12-22nd Main Idea…
Gravity _______ is a _____________________
between ________________________. ____ _________ on or near
_________________ are ________ toward __________________________ _________________________________.
Force – Part 23rd Main Idea…
Gravity & Mass The amount of ____________________
between ____ _________ depends on ____________________________________________.
When an apple falls, they both _________________________________.
However, because___________________ than the ______, the Earth_____________.
Force – Part 24th Main Idea…
Gravity & Distance The ____________________________
between _________________________ as the __________________________.
Force – Part 2
Forces – Part 21. DESCRIBE: In which direction does an object fall on Earth?
2. EXPLAIN: Why is the force of Earth’s gravity so strong?
Force – Part 3
Key Topic is…
How does a Spring Scale Work?
Our Objective is…
Describe how a spring scale is used to measure weight.
Force – Part 31st Main Idea…
The SI Unit of Force The _______ is the ________________. On Earth, ________________________
to lift a __________________________. ________ is a measure of the
_________________________________. Because it is a ______, the object’s
________ is measured in _________(N).
Force Part 32nd Main Idea…
Using a Spring Scale A ________ ________ measures the
_____________________________________________; this is also called its _________________.
Force – Part 33rd Main Idea…
Types of Spring Scales There are ______ _____ of _______
_________.
Ex. Lab scales, bathroom scales & market scales.
Weight pushes or pulls on a _______ causing a dial or pointer to turn until it shows the _______ of the object.
Ch. 12 Force Sec 12-3
Force – Part 31. IDENTIFY: What are you measuring when you weigh an object?
2. IDENTIFY: What does a spring scale measure?
3. What are three types of spring scales?
Force – Part 4
Key Topic is…
What is Friction?
Our Objective is…
Identify examples of friction.
Ch. 12 Force Sec 12-41st Main Idea…
Forces & Motion To stop a _______ ________, a _______
must act in the __________________to the direction of the __________.
Observe: Give your book a slight push. What happens? __________________.
What must you do to keep it moving? ________________________________.
Force – Part 4http://ffden-2.phys.uaf.edu/211_fall2002.web.dir/Ben_Townsend/StaticandKineticFriction.htm
http://www.school-for-champions.com/science/friction.htm
Ch. 12 Force Sec 12-42nd Main Idea…
Friction
• _______ is a_______________________ ____________________________.
Force – Part 43rd Main Idea…
Types of Friction
Types of friction when there is contact between surfaces:
_______ friction, a book ____________. ______ friction, a book _____________. ______ friction, contact between bike
________. ___ __________ (Fluid friction) pushes
_______ _______________ as it falls.
Force – Part 4
Force – Part 4
Force – Part 4
Force – Part 4
Force – Part 44th Main Idea…
Useful Friction _______ makes ___________________. Without ___________, you would not
be able to ___________________, _______________, _________________, or ___________________.
Force – Part 45th Main Idea…
Harmful Friction Unwanted _________ can be found in
________ ___________________. _______ _____ rub together and
______ ______ and can cause __________________________.
Ch. 12 Force Sec 12-4
Force – Part 5
Key Topic is…
How can friction be changed?
Our Objective is…
Describe some ways to change friction.
Force – Part 51st Main Idea…
Moving Against Friction Because friction
_______________________ to move _______, ______________ is needed to _________________________________.
Ch. 12 Force Sec 12-52nd Main Idea…
Using Rolling Friction One way to _______ ________ is to
__________ ________ ________ to _____________________.
_______ friction is ________________________ friction.
Force – Part 5
3rd Main Idea…
Using Lubricants __________ are ___________________. ____ is a ____________ that ________
________________________ from one another.
Force – Part 54th Main Idea…
Not Enough Friction Slipping on an icy sidewalk or a
____________ _____________ are examples of when there is _______________________________ surfaces.
To ________ ________ we sometimes _______ _______ on an _____ _____ or wear special __________________.
Force – Part 5www.superiorspecialty.com/. ../Incom/GritE.html
Force – Part 51. CALCULATE: If the force of friction is 16 N, how much force is needed to move the object?
2. IDENTIFY: When would it be helpful to use a lubricant?
3. HYPOTHESIZE: Why do staircases often have rubber mats on the steps?