Balance and Motion

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Balance and Motion
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Investigation 1 Balance
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arch

• A curved shape.

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balance

• To stay in a position without being held.

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balance point

• The place on which an object balances.

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clothespin

• A clip of wood or plastic for fastening clothes
  on a clothesline.

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counterweight

• Something that helps to balance an object.

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crayfish

• A freshwater shellfish.

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mobile

• A system of balance beams and objects.

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object

• Anything that can be seen or touched a thing.

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position

• The place where a person or thing is.

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stable

• Steady not falling over.

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system

• A set of objects that are related in some way and
  can be isolated for study a group of things or
  parts that form a whole.

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triangle

• A three-sided shape.

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unstable

• When something is not steady and falls over.

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weight

• How heavy something is.

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wire

• A bendable metallic strand or rod.

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Investigation 2 Spinners
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air resistance

• The force of air pushing on something.

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axis

• A straight line around which something rotates.

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disk

• An object that is a circle in only one direction
  and can fall over a disk can be a wheel.

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knot

• To firmly tie two pieces of material together.

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motion

• The act of moving.
• When something moves.

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rotate

• To turn in circles a lot of times to spin.

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shaft

• Something that acts as an axis.

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spin

• To turn by turning around an axis.
• To turn in circles a lot of times to rotate.

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swirl

• To spin or twist around and around.

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top

• A toy that spins.

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twirl

• To spin in the air.

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twirler

• A flying spinner.

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twist

• To wind or turn something around.

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whirl

• To move or turn around quickly or suddenly.

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wing

• The moveable appendages that birds and other
  animals use to fly.

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zoomer

• A toy made from a plastic disk and a piece of
  string it spins around when tension is released
  from the twisted string.

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Investigation 3 Rollers
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axle

• A rod or shaft to which wheels can be attached.

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loop

• An opening that is made by curving a piece of
  material into a circle.

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ramp

• An object that has a slope.

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runway

• A path over which something moves or lands.

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slope

• A surface that is higher on one end.

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sphere

• An object that is round in all directions and
  rolls in all directions.

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spiral

• To move in a circular motion around a fixed
  center point.

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wheel

• An object that is a circle in only one direction
  and can fall over a wheel is a disk.

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Science Stories
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force

• A push or a pull.

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gravity

• A force that pulls things toward the Earth.

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pitch

• How high or low a sound is.

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roll

• To move by turning over and over.
• When a wheel goes around on its edge.

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stable position

• Steady, not falling over.

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vibration

• A fast back and forth motion. Vibration makes
  sound.

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volume

• How loud or soft a sound is.