Lesson 10 of 12 · Forces
Experiment⭐ 30 XP⚡ Spark LabUpthrust and Floating
Upthrust and Floating.
🎯 Your mission
Predict it first. Then prove yourself right (or wrong).
⚡ The twist
The opposite of what you expect is often what happens.
Mind = Blown
🔥 A bolt of lightning is 5 times hotter than the surface of the sun.
Make a hypothesis first
Predict: what happens if you double the force?
What You'll Learn
A fluid pushes up on anything placed in it with a force equal to the weight of fluid displaced — Archimedes' principle. An object floats when it can displace its own weight of fluid before submerging, which is why a steel hull floats but a steel bar sinks.
Key Words
Tap a word to see its definition.
Materials Needed
- newton meter
- metal object
- displacement can
- measuring cylinder
- water
Safety First
- Mop spills at once — wet floors are a slip hazard.
- Keep water well away from any mains socket.
Steps
Read the explanation above and note the two key terms before you start.
Weigh a metal object in air on a newton meter, then weigh it again fully submerged. The difference is the upthrust. Collect the displaced water in a measuring cylinder and check its weight matches.
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 2Upthrust on a submerged object equals:
Where you see this in real life
This is why airplanes can fly and why rockets reach space.
Stretch Challenge
Try this in real life this week.
This week, find one thing in your house that turns one kind of energy into another.
For the dinner table
“Show me something at home that uses this kind of energy.”
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Upthrust and Floating
Predict it first. Then prove yourself right (or wrong).
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