An inclined plane is the science name for a ramp. Ann Gadzikowski's list of simple machines starts with it: "inclined plane, also known as a ramp"1. Your child has used one on every slide, driveway and stairway, and has probably built one from blocks this week.
Below: the idea in one dinner-table sentence, ramps to spot around town, the six simple machines and two experiments that measure the push.
What is an inclined plane?
NASA's Glenn Research Center describes them as flat sloping surfaces over which objects can be pushed or pulled to raise them to a higher level, and notes they raise objects with less force than a straight lift5. That is the whole job.
A ramp does not move. You do. Ask your child: "Would you rather lift your wagon onto the porch, or roll it up the ramp?"
A flat surface with one end higher than the other15.
Say it: “Where is the high end, and where is the low end?”The thing a machine helps you move1.
Say it: “What is the load on this ramp?”How sharply a ramp goes up. Gadzikowski teaches this word with block ramps1.
Say it: “Show me with your hand: steep or gentle?”The rubbing between surfaces that slows things down and costs you a little extra push7.
Say it: “Does the truck roll easier on the board or on the rug?”Inclined plane physics: less force, longer distance
A University of Illinois physicist explains the trade-off this way: a ramp reduces the force you need, but the distance you push to reach the same height grows by the same factor, so the energy you supply stays the same7.
That assumes no friction. Real ramps lose a little energy to friction, so you pay slightly more7.
- Short path: just the height
- Big force: the whole weight in your arms
- Long path: the whole slope
- Smaller force on every step
STEPS to STEM, a curriculum by Aaron Isabelle and Gilbert Zinn, describes the same kind of deal with bike gears:
This gain in speed is offset by a loss of force.2
The ramp trades the other way: you give up distance and get an easier push. Say it to your child like this: "The ramp doesn't make the job smaller. It cuts it into lots of easy little pieces."
A ramp never saves energy. It spreads the effort out.
Examples of inclined plane at home and around town
Once your child knows the idea, ramps show up everywhere. Make it a hunt on the walk to school.
| Where | What goes up or down it | Ask your child |
|---|---|---|
| Wheelchair ramp at a library or store | Wheelchairs, strollers, carts | Why is it so long and gentle?9 |
| Stairs | Your feet, one step at a time | NASA lists stairs as an example4. Where is the slope hiding? |
| Block corner or tile ramp | Toy cars and balls | Which ramp would you drive on? Why?1 |
| Mountain road that zigzags | Cars and bikes | Which path is longer, straight up or the zigzag?6 |
| Jar lid or screw | The lid, twisting on | Can you trace the ramp spiraling around?15 |
| Playground slide | You | Steep or gentle? Which slide is faster?8 |
The wheelchair ramp is the trade-off written into building rules. The US Access Board's guide caps the running slope at 1:12 and recommends gentler slopes for a wider range of users9. Gentle is easier on every push, but longer. Pace one out with your child.
The 6 simple machines, one example each
What counts as a simple machine in science
NASA's educator notes define a simple machine as an object that helps complete a task by changing the direction of motion or the amount of force needed, and name six: screw, inclined plane, wedge, lever, wheel and axle, and pulley4. DK's 1000 Words STEM says it in kid words3:
We build machines to help us.3
| Machine | What it does | Example to find |
|---|---|---|
| Inclined plane | Raises things with less force, along a longer path57 | A ramp or stairs4 |
| Wedge | Two sloping surfaces meeting at an edge, to split or separate45 | A door stop or a knife4 |
| Screw | A ramp wrapped around a shaft5 | A jar lid or bottle cap14 |
| Lever | A bar on a pivot point, the fulcrum, that moves a load4 | A seesaw or scissors4 |
| Wheel and axle | A wheel on a rod, turning to move a load4 | A bicycle or a clock4 |
| Pulley | A wheel with a rope that changes the direction of a pull14 | An elevator or a water well4 |
Kids should memorize all six names.
Gadzikowski, writing for preschool and kindergarten teachers, says teaching the names is neither necessary nor developmentally appropriate; hands-on experimenting is what builds understanding1.
A ramp just sits there, so it is not really a machine.
No simple machine creates energy. A ramp counts because it changes the force you need, while the distance grows to match7.
Ramp experiment 1: the rubber band pull test
A rubber band is your force meter: the harder you pull, the longer it stretches. Same height, three paths.
The rubber band pull test
- A toy truck or car, loaded with a few wooden blocks
- 1 long rubber band
- A ruler
- A stack of books about 6 inches high
- A short board and a long board (or two strips of stiff cardboard)
- Tape
- Loop the rubber band around the front of the truck, or tape it on.
- Ask for a prediction: which path will stretch the band the most?
- Straight lift: hold the band and lift the truck slowly from the floor to the top of the books. Your helper measures the band with the ruler.
- Short ramp: lean the short board on the books. Pull the truck slowly and steadily up it, and measure the band halfway up.
- Long ramp: same books, same height, longer board. Pull and measure again.
- Do 3 tries for each path. Same truck, same load, same slow pull.
| Path | Band length, try 1 | Try 2 | Try 3 | Middle number |
|---|---|---|---|---|
| EXAMPLE: straight lift | 5 in | 6 in | 5 in | 5 in |
| Straight lift | ____ | ____ | ____ | ____ |
| Short ramp | ____ | ____ | ____ | ____ |
| Long ramp | ____ | ____ | ____ | ____ |
Middle number: sort the three tries, take the middle one. Then measure each path with string. The long ramp wins on force and loses on distance7.
Which ramp makes a car roll farthest? That question has its own fair test, in our ramps and cars guide.
Ramp experiment 2: wrap a ramp into a screw
This one comes from a NASA Glenn classroom lesson, and it surprises adults too6.
The paper screw
- Paper
- A pencil
- Tape
- A crayon or marker
- Scissors (an adult cuts)
- An adult cuts a right triangle from the paper, about as long as a hand.
- Your child colors the longest side. That slanted edge is the ramp.
- Tape one of the short sides to the pencil.
- Roll the pencil so the triangle wraps around it, then tape the end down.
- Look at the colored edge. It winds up the pencil in a spiral, like the thread on a screw6.
-
01Which path is longer?
Measure the colored edge with string, then the height of the spiral on the pencil. NASA's lesson asks the same question6. The long edge is the gentle path.
-
02Where else do spirals climb?
Look for roads that zigzag down mountains or spiral around them, another idea from the lesson6.
What to expect by age
Can: Spot ramps, use words like steep and gentle, and say which ramp would be easier to drive on1.
Try: Do the paper screw and the ramp hunt. For the pull test, skip the ruler: which path feels easier on your hand?
Can: Measure band length, find the middle of three tries and explain less force over a longer distance7.
Try: Measure each path's length and height, then predict the stretch for a third ramp before testing it.
Frequently asked questions
What is an inclined plane in simple words?
It is a ramp: a flat sloping surface used to raise things with less force than lifting them straight up15. The price is a longer path7.
What are some examples of inclined plane at home?
Ramps and stairs are NASA's own examples4. Also look at slides, block ramps and jar lids, whose thread is a wrapped ramp15.
How does inclined plane physics work?
A ramp reduces the force you need, and the distance you push grows by the same factor, so without friction the energy stays the same7.
Is an inclined ramp a simple machine in science?
Yes. NASA lists it as one of six simple machines4. A simple machine changes the direction of motion or the amount of force needed4.
Why does a car go faster down a steeper inclined plane ramp?
On a steeper ramp, more of gravity's pull points along the slope, so the car speeds up faster8. To test it fairly, change only the height.
Keep exploring
- Ramps, cars and your child's first fair test Which ramp makes a car roll farthest? Set up a fair test.
- Center of gravity for kids The lever's cousin: why a heavy thing close to the pivot balances a light thing far away.
- The Engineering Design Loop at Home Turn a ramp into a design challenge: ask, build, test, improve.
If you want a kit for this
Books and a board cover everything above. If you want ramps that snap together in seconds, our Magnetic Travel Tiles come with cars for side-by-side ramp tests.
Build it with / Ages 5-7Magnetic Travel Tiles with CarsFlat shapes that stand up into roads and garages.$41.99GoP Toys sells the kit mentioned above. None of the sources cited tested our products.