K-PS2-1: Testing Pushes and Pulls
Also called NGSS K-PS2-1 · Topic: Forces and Interactions: Pushes and Pulls · Physical Science
The Official Wording
Plan and conduct an investigation to compare the effects of different strengths or different directions of pushes and pulls on the motion of an object.
Clarification statement: Examples of pushes or pulls could include a string attached to an object being pulled, a person pushing an object, a person stopping a rolling ball, and two objects colliding and pushing on each other.
Assessment boundary: Assessment is limited to different relative strengths or different directions, but not both at the same time. Assessment does not include non-contact pushes or pulls such as those produced by magnets.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What K-PS2-1 Means in Plain English
Kindergartners plan and carry out a simple test of how pushes and pulls change the way something moves. They compare a gentle push with a hard one, or a push from one side with a push from the other, and watch what the object does.
The test changes one thing at a time: either how hard the push is or which way it goes, never both together. Magnets and other pushes without touching wait for later grades. Next, children use what they learn to design something that changes a motion (K-PS2-2).
K-PS2-1 I Can Statements
- I can plan a test with a push or a pull.
- I can compare what a soft push and a hard push do.
- I can tell how the direction of a push changes the way something moves.
K-PS2-1 Worked Example
A push test a class can run on the rug with one toy car, a ruler and painter's tape.
Does a harder push make a toy car roll farther than a gentle push?
Set It Up: A toy car, a strip of painter's tape as the start line, and a ruler laid flat on the floor to push with.
- Line the car up on the tape, nose to the line.Same start every time
- Give it a gentle tap with the ruler and mark where it stops with a sticky note.Gentle push: short roll
- Bring it back to the tape and give it a big push with the same ruler.Hard push: long roll
- Do each push two more times so one lucky roll does not decide.3 gentle, 3 hard
- Compare the sticky notes for each kind of push.Hard-push notes sit farther away
The harder push sent the car farther every time.
Why it works: A bigger push gives the car a bigger start, so it goes faster and keeps rolling longer before it stops.
Common Mistakes with K-PS2-1
Changing two things at once
A hard push to the left, then a soft push straight ahead
Try this: Keep the direction the same and change only how hard you push, then run a second test that changes only the direction.
Trusting a single try
“The soft push went farther!” after one roll
Try this: Run each push three times from the same start line and look at all the stopping spots before deciding what happened.
Pushing with different things
A finger flick first, then a shove with the whole hand
Try this: Use the same pusher for every try, like one ruler, so the only difference is how hard or which way you push.
Where K-PS2-1 Fits
Practice K-PS2-1
Quick Check
- You push a ball gently, then hard. Which push makes it roll farther?
- You want to test what a push's direction does. What do you keep the same?
- Why roll the car three times for each push?