3rd grade · Science · Unit 2 of 8
Pushes, Pulls & Forces
Gravity, magnets, friction and changing motion
What your child practices
Forces as pushes and pulls, contact and non-contact forces (gravity, magnetism, static electricity), friction, how bigger forces change motion more, and helmets and seat belts as safety devices.
Maine Learning Results learning standard: 3-PS2-1; 3-PS2-3 · balanced and unbalanced forces, and magnetic forces that act without touching
How we explain it
Children can open this short lesson before they practice.
- A force is a push or a pull. A bigger force changes motion more.
- Contact forces need touching. Gravity, magnetism and static work without touching.
- Friction slows moving things. Helmets and seat belts spread out forces to protect us.
Example: A magnet pulls a paper clip from a short distance. Contact or non-contact force? The magnet does not touch the clip. Answer: non-contact
Pushes, Pulls & Forces in Maine
In the Maine Learning Results, this is unit 2 of 8 in 3rd grade Science, after How Plants Grow & Change and before Basic Needs & Life Cycles.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Maine Department of Education
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
To reduce damage from flooding along a river, people can…
🌊- remove all dams
- cut down trees on the bank
- pour more water on the banks
- build barriers and keep homes away from the riverbank
build barriers and keep homes away from the riverbank
Hint: Flood forces from fast water are hard to stop; planning where to build helps keep people safe.
Question 2
Which surface has the most friction?
🧱- sandpaper
- polished glass
- ice
- a wet bar of soap
sandpaper
Hint: Rough surfaces grip and slow things down. Slippery surfaces have little friction.
Question 3
Which needs a bigger force to push: an empty wagon or a wagon full of rocks?
🛒- neither needs a force
- the wagon full of rocks
- they need the same force
- the empty wagon
the wagon full of rocks
Hint: Heavier things need a larger force to start moving.
Question 4
A ball rolls across the grass and slowly stops. What force slows it down?
⚽- friction
- static electricity
- a push from the Moon
- magnetism
friction
Hint: Friction between the ball and the grass slows it.
Question 5
Which kind of force can change a flat piece of clay into a ball?
🧱- squeezing and pushing
- gravity only
- a smell
- a magnet
squeezing and pushing
Hint: Pushing and squeezing change shape.
Question 6
A force is a…
💪- shadow or a light
- sound or a taste
- push or a pull
- color or a smell
push or a pull
Hint: Every force is a push or a pull on an object.