Lesson 4 of 12 · Forces
Experiment⭐ 30 XP⚡ Spark LabWeight Is Not Mass
Weight Is Not Mass.
🎯 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
Mass is the amount of matter, in kilograms, and does not change with location. Weight is the gravitational force on that mass, in newtons, and equals mg. A 60 kg astronaut still has 60 kg of mass on the Moon but weighs about a sixth as much.
Key Words
Tap a word to see its definition.
Materials Needed
- newton meter
- slotted masses
- clamp stand
- graph paper
Safety First
- Secure the clamp stand with a counterweight so it cannot topple.
- Keep feet clear beneath hanging masses.
Steps
Read the explanation above and note the two key terms before you start.
Hang known masses from a newton meter and record the reading for each. Plot weight against mass, find the gradient, and identify it as the local gravitational field strength.
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 2A 60 kg astronaut travels to the Moon. Her mass there 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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Weight Is Not Mass
Predict it first. Then prove yourself right (or wrong).
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