Lesson 6 of 12 · Forces
Experiment⭐ 30 XP⚡ Spark LabFriction: Static, Kinetic, and Useful
Friction: Static, Kinetic, and Useful.
🎯 Your mission
Run the experiment. Find out what really happens.
⚡ The twist
Speed isn't the same as force. Don't mix them up.
Mind = Blown
⚡ Static electricity is the same physics as lightning, just smaller.
Make a hypothesis first
Guess: where does the energy go?
What You'll Learn
Friction opposes relative sliding between surfaces. Static friction holds things in place up to a maximum; once sliding starts, kinetic friction is usually smaller. Friction is not simply a nuisance — without it you could not walk, grip or brake.
Key Words
Tap a word to see its definition.
Materials Needed
- plank
- wooden block
- protractor
- sandpaper
- cloth
Safety First
- Support the raised end so the plank cannot slip off its rest.
Steps
Read the explanation above and note the two key terms before you start.
Tilt a plank slowly with a block on it and record the angle at which sliding just begins, then the smaller angle at which sliding just continues. Repeat for three surface pairs and rank them.
Record what actually happened, including anything that did not match what you expected.
Write a conclusion that answers the question this lesson opened with, and state your uncertainty.
Check Your Understanding
Question 1
1 of 2For most surface pairs, kinetic friction is:
Where you see this in real life
You use this every time you flip a light switch, ride a bike, or kick a ball.
Stretch Challenge
Try this in real life this week.
Time how long a small ball rolls down something, then change the slope and try again.
For the dinner table
“Show me something at home that uses this kind of energy.”
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Friction: Static, Kinetic, and Useful
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