7 th grade Week 26 Notes Where have

Where have we been? Waves: Energy Types: Heat Moves Parts: Forms: Properties

What is a force? A force is a push or a pull; A force

Types of Forces There are two types of forces: Contact & Non-contact forces

Types of Forces Contact Forces- forces that come in contact with the object •

Types of Forces Contact Forces • FRICTION- force from two objects rubbing against each

Types of Forces Contact Forces • NORMAL – force of an a surface pushing

Types of Forces Non-Contact Forces- forces that act on objects from a distance •

Assignment: Forces 1 What forces are acting on the image above?

Forces against forces A force is a push or pull Forces have magnitude/intensity (the

Forces against forces The intensity of a force is measured in a unit called

Forces against forces Vector: To show the intensity, you draw an arrow. The length

Forces against forces Forces always work in PAIRS • Depending on the direction or

Forces against forces Forces can be “balanced” • NO MOVEMENT • Magnitude/intensity are equal

Forces against forces Forces can be “balanced” • CONSTANT SPEED • Magnitude/intensity stays the

Forces against forces Forces can be “unbalanced” • Force and/or Direction is different •

Write a paragraph about what these arrows are showing about forces A B C

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7 th grade Week 26 Notes

Where have we been? Waves: Energy Types: Heat Moves Parts: Forms: Properties

What is a force? A force is a push or a pull; A force can make objects move or stop A force is a VECTOR- it has intensity & direction A Force is anything that changes the speed and/or direction so it CAUSES acceleration

Types of Forces There are two types of forces: Contact & Non-contact forces

Types of Forces Contact Forces- forces that come in contact with the object • FRICTION • AIR RESISTANCE • NORMAL • TENSIONAL • APPLIED

Types of Forces Contact Forces • FRICTION- force from two objects rubbing against each other • AIR RESISTANCE- force from air molecules rubbing against a moving object

Types of Forces Contact Forces • NORMAL – force of an a surface pushing up. Examplea book resting on a table, the table is keeping the book up • TENSIONAL- force of a string or line • APPLIED- force applied by muscles

Types of Forces Non-Contact Forces- forces that act on objects from a distance • GRAVITY • MAGNETISM • ELECTRICITY • Nuclear

Types of Forces Non-Contact Forces- forces that act on objects from a distance • GRAVITY- force of attraction between two objects • MAGNETISM- force of attraction between magnetic materials • ELECTRICITY- force of pushing electrons • Nuclear- force that holds atoms together

Assignment: Forces 1 What forces are acting on the image above?

Forces against forces A force is a push or pull Forces have magnitude/intensity (the size of the force) Forces have a direction

Forces against forces The intensity of a force is measured in a unit called a Newtons. The direction of a force can be indicated as left, right, up, down, north, south, etc. To show the intensity and direction we use an arrow called a VECTOR.

Forces against forces Vector: To show the intensity, you draw an arrow. The length of the arrow shows the intensity: Example: The shorter arrow shows less intensity The tip shows the direction…

Forces against forces Forces always work in PAIRS • Depending on the direction or intensity three things can happen: No movement Movement in a direction or a change of speed Steady speed and direction Steady change in speed

Forces against forces Forces can be “balanced” • NO MOVEMENT • Magnitude/intensity are equal • Direction is opposite

Forces against forces Forces can be “balanced” • CONSTANT SPEED • Magnitude/intensity stays the same • Direction is opposite

Forces against forces Forces can be “unbalanced” • Force and/or Direction is different • Results: a) you have a change in speed; b) you have a change in direction or c) both

Write a paragraph about what these arrows are showing about forces A B C D E