Forces & MotionForces & Motion

Big IdeasBig Ideas

Every force is part of an interaction Every force is part of an interaction between two objectsbetween two objects

Forces are pushes and pulls that can Forces are pushes and pulls that can be contact or non-contact forcesbe contact or non-contact forces

Motion is described relative to Motion is described relative to something else (point of reference)something else (point of reference)

A change in motion is due to A change in motion is due to unbalanced forcesunbalanced forces

No change in motion and an object at No change in motion and an object at rest are due to balanced forcesrest are due to balanced forces

ForcesForces

Force: a push or pull that causes an Force: a push or pull that causes an object to accelerate in the direction of object to accelerate in the direction of the forcethe force

Contact Forces: pushes and pulls that Contact Forces: pushes and pulls that result from direct touching of objectsresult from direct touching of objects

Friction: the force of two surfaces in Friction: the force of two surfaces in contact with each othercontact with each other

Non-contact Forces: pushes and pulls Non-contact Forces: pushes and pulls that result without the direct touching that result without the direct touching of objects acting at a distanceof objects acting at a distance

Magnetic attraction: a force that Magnetic attraction: a force that pulls objects with opposite poles pulls objects with opposite poles towards on anothertowards on another

Magnetic repulsion: a force that Magnetic repulsion: a force that pushed objects with the same poles pushed objects with the same poles away from one anotheraway from one another

Gravitational force: a force that pulls Gravitational force: a force that pulls objects toward each other. This objects toward each other. This force acts between all objects.force acts between all objects.

Identify the following as Identify the following as Contact or Non-Contact Contact or Non-Contact

ForcesForces A foot kicking a A foot kicking a

soccer ballsoccer ball An apple falling off a An apple falling off a

treetree A paper clip sliding A paper clip sliding

towards a magnettowards a magnet A bat stricking a A bat stricking a

baseballbaseball Two magnets Two magnets

pushing apart from pushing apart from one anotherone another

The moon orbiting The moon orbiting the Earththe Earth

A compass needle A compass needle turning Northturning North

A hand pushing an A hand pushing an objectobject

Shoes rubbing Shoes rubbing against the flooragainst the floor

Contact ForcesContact Forces FrictionFriction Drag (air Drag (air

resistance)resistance) Physical Contact Physical Contact

with an objectwith an object

Non-Contact Non-Contact ForcesForces

GravityGravity MagnetismMagnetism

MagnetismMagnetism

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Create a CartoonCreate a Cartoon

Today you are making a cartoon strip. Today you are making a cartoon strip. Your cartoon strip should be about a Your cartoon strip should be about a super hero who uses the power of forces super hero who uses the power of forces to save people. Your cartoon should have to save people. Your cartoon should have eight sections that include examples of: eight sections that include examples of:

3 Contact Forces3 Contact Forces 3 Non-Contact Forces3 Non-Contact Forces Labels for each forceLabels for each force ColorColor

Balanced & Unbalanced Balanced & Unbalanced ForcesForces

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Net force: the combination of all forces Net force: the combination of all forces acting on an object. This determines if an acting on an object. This determines if an object moves and in which directionobject moves and in which direction

Non-zero net force: when forces act in the Non-zero net force: when forces act in the same direction the net force is found by same direction the net force is found by adding the strengths of the individual adding the strengths of the individual forces. When forces act in opposite forces. When forces act in opposite directions, they combine by subtraction.directions, they combine by subtraction.

Zero net force: when the combined forces Zero net force: when the combined forces are zero. The motion of an object will not are zero. The motion of an object will not change. (If it is at rest it stays at rest, if it is change. (If it is at rest it stays at rest, if it is in motion it stays in motion)in motion it stays in motion)

Balanced force: equal forces acting on one Balanced force: equal forces acting on one object in opposite directions. These do not object in opposite directions. These do not change the object’s motionchange the object’s motion

Unbalanced forces: whenever a net force Unbalanced forces: whenever a net force acts on an object. This can cause it to start acts on an object. This can cause it to start moving, stop moving or change directionmoving, stop moving or change direction

Unbalanced ForcesUnbalanced Forces

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