# Forces Lesson 1.

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Forces Lesson 1

Essential Question How Do Objects React To Forces? What is a force?
What are the Main Types of Forces? What Factors Affect Gravity?

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What Is a Force? When one object pushes or pulls another object, the first object exerts a force on the second. Shown with arrows (direction & force) SI units called newton after Sir Isaac Newton.

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What are the Main Types of Forces
Contact Forces (Friction) Forces at a Distance

Contact Forces Applied Forces Normal Forces Friction Objects Touch

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Applied Forces A force that is put on an object by another object. Push--Pull

Normal Force The force that acts between objects when they are in contact with each other.

Friction The force that two surfaces exert on each other when they rub against each other.

What If There Was No Friction?

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Forces at a Distance Electrical Forces Magnetic Forces
Gravitational Forces Objects Don’t Touch

Electrical Forces The force between two charged objects

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Magnetic Force The attraction or repulsion between two magnetic poles

Extra Credit: Build a Magnet
Things You'll Need Iron nail, wire, wire cutters, Knife, Battery, Tape, Paper clips, Adult Supervision

Gravitational Force The force that pulls objects toward each other.
Sorry I was attracted to you! The law of universal gravitation states that the force of gravity acts between all objects in the universe that have mass!

Two Factors Affect Gravity
Mass: the more mass the greater the gravitational force. Distance: the greater the distance the less gravitational force.

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May The Force Be With You!

Try it! * An empty soda can * Blown-up balloon * A head of hair
1. Place the can on its side on a flat smooth surface like a table or a smooth floor.  2. Rub the blown up balloon back and forth through your hair really fast. 3. Now the fun part - Hold the balloon close to the can without actually touching the can. The can will start to roll towards the balloon without you even touching it! Try This Too: While you've got the balloon out, tear up part of a tissue into tiny pieces about 1/4 inch (.5 cm) big. Rub the balloon in your hair again and bring it close to the tissue pieces. They will be attracted to the balloon and then jump away. * An empty soda can * Blown-up balloon * A head of hair

Home Learning Complete Lesson 1 Assess Your Understandings
Review & Assessment #1 Page Vocabulary Cards Lesson 1 Extra Credit: Gizmo #10 2/12 Extra Credit: Magnet 2/24 Extra Credit: Gizmo #11 2/27 Science in the News 2/27