K-PS2-2: Designing to Change a Ball's Motion
Also called NGSS K-PS2-2 · Topic: Forces and Interactions: Pushes and Pulls · Physical Science
The Official Wording
Analyze data to determine if a design solution works as intended to change the speed or direction of an object with a push or a pull.
Clarification statement: Examples of problems requiring a solution could include having a marble or other object move a certain distance, follow a particular path, and knock down other objects. Examples of solutions could include tools such as a ramp to increase the speed of the object and a structure that would cause an object such as a marble or ball to turn.
Assessment boundary: Assessment does not include friction as a mechanism for change in speed.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What K-PS2-2 Means in Plain English
Kindergartners test a simple design that changes how a ball or marble moves, then look at what happened to decide if it worked. A ramp might be meant to speed a marble up, and a wall might be meant to turn it toward a target.
Children judge a design by what they see: did the marble go faster, go farther, or change direction? Friction as a reason for slowing down is left for later grades. This builds on the push tests in K-PS2-1 and leads to the forces work in 3-PS2-1.
K-PS2-2 I Can Statements
- I can tell if my ramp made the marble go faster.
- I can build a wall that turns a rolling marble.
- I can use test results to say if a design worked.
K-PS2-2 Worked Example
A design test a class can run on a table with a marble, a cardboard ramp and a few blocks.
Can a wall of blocks turn a marble so it knocks over a paper cup off to the side?
Set It Up: A marble, a cardboard ramp propped on two books, a few wooden blocks, and a paper cup standing to one side of the ramp's end.
- Roll the marble down the ramp with no wall and watch where it goes.It rolls straight past the cup
- Build a block wall at a slant just past the bottom of the ramp.Wall in place, angled toward the cup
- Roll the marble three times from the top and mark each hit or miss on a chart.Hit, miss, hit
- Move the wall a little and roll three more times.Hit, hit, hit
- Compare the two charts to decide which wall did the job.Second wall: 3 hits out of 3
The slanted wall turned the marble, and after one small move it hit the cup every time.
Why it works: When the rolling marble bumps the wall, the wall pushes back on it and sends it off in a new direction.
Common Mistakes with K-PS2-2
Judging without testing
“My ramp is fast, I can tell!” before any rolls
Try this: Roll the marble several times and watch or mark the results before deciding if the design did its job.
Forgetting what the design was for
Calling the wall a success because the marble went fast
Try this: Say the goal out loud before testing, like “turn the marble toward the cup,” and check the results against that goal.
Changing the start each time
Letting the marble go halfway down the ramp, then from the top
Try this: Let the marble go from the same spot at the top of the ramp every time, so only the design changes.
Where K-PS2-2 Fits
Practice K-PS2-2
Quick Check
- A marble rolls straight past the cup. What could you build to make it turn?
- How can you find out if a steeper ramp makes a marble go faster?
- Your wall made the marble hit the cup once in three tries. Did it work?