Pick a thing
Pick a surface
Your runs
| Run | Thing | Surface | Height | Mass | Distance |
|---|---|---|---|---|---|
| No runs yet. Press Go. | |||||
Why did it do that?
Gravity pulls it down
Gravity pulls everything toward the ground. On a ramp, some of that pull points down the slope. A steeper ramp means more of the pull points down the slope. That makes it go faster.
Friction takes speed away
Friction is rubbing between two surfaces. Rough carpet and sandpaper rub a lot. Smooth wood rubs less. Ice-like rubs almost none. Wheels and round things roll, so they rub less than a block that slides.
Heavy or light, same trip
A heavy thing is pulled harder by gravity. It is also harder to get moving. The two cancel out. Try the mass slider and watch the distance. Surprised? Scientists were too.
Teacher note. Pairs with any classroom ramp investigation. Students change one variable at a time, ramp height or surface, and measure how far a toy car travels. Key ideas: forces, friction and slope. Ask students to predict before each run and to explain the mass result.