
Surface Roughness and Car Speed
Medium
How much does surface roughness slow down a rolling car? Friction (the force that resists motion) depends on the texture of the ground.
You line a ramp with sandpaper of five different grit levels. Finer grit means a smoother surface. Then you release three model cars and time how long each takes to roll two meters.
As the surface gets rougher every car slows down. The results show how much extra time each grit level adds.
Hypothesis
The hypothesis is that cars move faster on a fine surface and more slowly on a coarse surface.
Method & Materials
You will set up a ramp with different surfaces, measure the time it takes for cars to travel two meters down the ramp, and compare the results.
You will need a ramp, three types of model cars, seven pieces of sandpaper with different grit sizes, a stopwatch, a ruler, an assistant, and masking tape.
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See what’s includedResults
The results showed that as the surface of the ramp became more coarse, the cars took a longer time to travel two meters down the ramp. This observation stands out and supports the hypothesis that cars move faster on a fine surface and more slowly on a coarse surface.
Why do this project?
This science project is interesting because it explores how different surfaces affect the speed of cars. It also shows how friction plays an important role in the motion of cars.
Also Consider
Experiment variations include using remote controlled cars and increasing the gradient of the ramp.
Full project details
Additional information and source material for this project are available below.Related videos
These videos explain the science behind this project and demonstrate key concepts used in the experiment.
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