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STEM Grade 3




Trimester 2/3: UNIT SUMMARY


The students will be able to understand how forces affect our everyday
lives. These forces can be observed to predict the pattern of motion and the interaction
between two objects.


3-PS2-1: Plan and conduct an investigation to provide evidence of the effects of balanced and
unbalanced forces on the motion of an object. [Clarification Statement: Examples could include an
unbalanced force on one side of a ball can make it start moving; and, balanced forces pushing on a box
from both sides will not produce any motion at all.] [Assessment Boundary: Assessment is limited to one
variable at a time: number, size, or direction of forces. Assessment does not include quantitative force
size, only qualitative and relative. Assessment is limited to gravity being addressed as a force that pulls
objects down.]

3-PS2-2: Make observations and /or measurements of an object’s motion to provide evidence that
a pattern can be used to predict future motion. Clarification Statement: Examples of motion with a
predictable pattern could include a child swinging in a swing, a ball rolling back and forth in a bowl, and
two children on a see-saw.] [Assessment Boundary: Assessment does not include technical terms such
as period and frequency.]

3-PS2-3: Ask questions to determine cause and effect relationships of electric or magnetic
interactions between two objects not in contact with each other. [Clarification Statement: Examples
of an electric force could include the force on hair from an electrically charged balloon and the electrical
forces between a charged rod and pieces of paper; examples of a magnetic force could include the force
between two permanent magnets, the force between an electromagnet and steel paperclips, and the
force exerted by one magnet versus the force exerted by two magnets. Examples of cause and effect
relationships could include how the distance between objects affects strength of the force and how the
orientation of magnets affects the direction of the magnetic force.] [Assessment Boundary: Assessment is
limited to forces produced by objects that can be manipulated by students, and electrical interactions are
limited to static electricity.]

3-PS2-4: Define a simple design problem that can be solved by applying scientific ideas about
magnets. [Clarification Statement: Examples of problems could include constructing a latch to keep a
door shut and creating a device to keep two moving objects from touching each other.]





How do forces affect us in our everyday lives?



By the end of this trimester, your child will know the following:

Students will understand…

 Unbalanced and balanced forces impact the motion of an object.
 A pattern of a motion can be observed and used to predict future motion.
 The cause and effect relationships of electric or magnetic interaction between two objects that not in contact with each other.



Attract-to pull something closer
Force- a push or a pull
Magnet- a piece of metal that attracts other pieces of metal
Magnetism-a force that pushes or pulls certain metals
Metal-a material, usually hard and shiny, that lets electricity and heat move
through it
Poles-two opposite parts of something, such as the two ends of a magnet
Repel-to push something away
Pull-to use force to move something closer
Push-to use force to move something away
Barrier- a fence or other obstacle that prevents movement or access.


Click the AWESOME links  below to learn more about and practice S.T.E.M. concepts:


Simple Machines

Forces in Action

Pushes and Pulls

Work, Force, Energy and Motion


Ship Loader

Truck Loader 4

Truck Loader

Solids and Liquids

Destructive and Constructive Landforms