Lesson 7 of 12 · Forces
Experiment⭐ 30 XP⚡ Spark LabMoments and Turning Forces
Moments and Turning Forces.
🎯 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
The moment of a force about a pivot is force times perpendicular distance, in newton metres. A balanced object obeys the principle of moments: total clockwise moment equals total anticlockwise moment. That is why a long spanner loosens a tight nut.
Key Words
Tap a word to see its definition.
Materials Needed
- metre rule
- pivot or knife edge
- slotted masses
- hangers
Safety First
- Keep masses low over the bench so a slip cannot drop them on toes.
Steps
Read the explanation above and note the two key terms before you start.
Balance a metre rule on a pivot at its centre, hang masses at measured distances on both sides, and adjust until it balances. Record five balanced arrangements and check that force times distance matches on each side.
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 2The moment of a force is calculated as:
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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Moments and Turning Forces
Predict it first. Then prove yourself right (or wrong).
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