Describing motion and force

​Describing Motion and Force

Further reading in your textbook chapters. ​

Open Ended

How can you tell something is moving?

​We say an object is in motion if the position changes when compared to another object.

​​Reference point

​​Motion

​

​A reference point is a place or object used for comparison to determine whether something is in motion.

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EXAMPLES:​

• ​A tree

• A building

• Really anything that is fixed to the earth.​

​Suppose you are in a car with your dog and your reference point is a tree outside. Are you in motion?

​​Car and tree

​Now suppose you look over at the other seat and you see your other dog. If your reference point is the seat the dog is sitting on are you in motion?

​​Car and dog

Multiple Choice

If you are sitting on your beach towel by a lake and your reference point is your beach towel are you in motion?

• Yes

• No

Multiple Choice

If you are change your reference point to the sun while sitting on your beach towel are you in motion?

• Yes

• No

Open Ended

How would you determine if something is in motion or not?

Objects move in relation to each other but they also can slow down, speed up, and change direction. ​

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​Force

​

A FORCE is a ​push or pull.

​

Examples:

• Pushing your book into your locker

• Pulling a door open​

• ​Described by its order and direction

  ​

• Turning a faucet to the left vs the right is different types of force.

  ​

• Opening a fridge door ​is more force than lifting a bowl.

​​Force is...

​

​The International System of Units calls the unit for strength of a force a newton after Sir Isaac Newton.

​​Newtons

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Reorder

Reorder the following from MOST force applied to LEAST force applied

• A car parked on a driveway.

• A horse pulling a cart

• You sitting on your chair

• A bird sitting on a tree branch

• A spider standing on your backpack

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

​Contact forces are applied when one object touches another.

​​Contact force

Friction: a contact force that two surfaces exert on each other when they rub against the other. ​

• Rubbing your hands together quickly.

• Walking and not slipping​

​​Example

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​Noncontact forces are applied to an object whether it touches the object or not.

​​Noncontact force

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​Gravity: A force that pulls objects toward each other as a result of their masses.

• ​You and the Earth

• ​Magnets

• Electricity​

​​Example

Open Ended

What are the three examples of noncontact forces?

Open Ended

Give an example of a contact force you use in your every day life.

Multiple Choice

The force that causes objects with mass to attract one another.

• Weight

• Gravity

• Mass

• Magnetism

Multiple Choice

Gravity attracts all objects towards one another.

• False

• True

• It depends

Multiple Choice

Any object with mass has gravity.

• True

• Sometimes

• False

• Never

Multiple Choice

leaves blowing in the wind is an example of a

• contact force

• noncontact force

Multiple Choice

magnet attracting a nail

• contact

• noncontact

Multiple Choice

a leaf falling from a tree

• contact

• noncontact

Multiple Choice

a bat hitting a baseball

• contact

• noncontact

Multiple Choice

pushing in a chair

• contact

• noncontact

• ​A book sitting on a shelf

• A person sitting on a chair

• Tug of war where there is a tie

​​Forces that are equal but in opposite directions

​

• Pulling a book off a shelf

• Sitting in a chair but it breaks

• Tug of war with your little brother

​​Forces that are unequal

Multiple Choice

Two chipmunks push on an apple in opposite directions with forces of equal strength.

• Balanced

• Unbalanced

Multiple Choice

A chipmunk and a racoon push on an apple in opposite directions

• Balanced

• Unbalanced

Multiple Choice

A card sliding across a table.

• Unbalanced force

• Balanced force

Multiple Choice

A cat shoving a glass off a table

• Unbalanced force

• Balanced force

Multiple Choice

The unit for force is a called a: 

• Galileo

• Newton

• Aristotle

Multiple Choice

When Izzy and Zoe pull on the rope with the same amount of force, the forces are _____.

• increased

• unbalanced

• balanced

• decreased

Multiple Choice

What is a force?

• the PUSH or PULL on an object 

• The MOTION an object creates

• The objects HITTING one another

• Going REALLY FAST

Multiple Choice

A person standing still while leaning on a wall

• Unbalanced force

• Balanced force

Multiple Choice

Waving a flag

• Unbalanced force

• Balanced force