Lesson 3 of 10 · Energy
Experiment⭐ 30 XP⚡ Spark LabGravitational Potential Energy
Gravitational Potential Energy.
🎯 Your mission
Run the experiment. Find out what really happens.
⚡ The twist
The opposite of what you expect is often what happens.
Mind = Blown
🎢 You feel weightless on a roller coaster because you and the seat are falling at the same speed.
Make a hypothesis first
Predict: what happens if you double the force?
What You'll Learn
Lift a mass and you store energy in the gravitational field: Ep = mgh. The store depends only on the vertical height gained, not on the path taken, so carrying a rucksack up a zigzag trail stores the same energy as hauling it straight up.
Key Words
Tap a word to see its definition.
Materials Needed
- tape measure
- bathroom scale
- stopwatch
- staircase
Safety First
- Use a handrail; do not run up stairs if they are wet or crowded.
Steps
Read the explanation above and note the two key terms before you start.
Measure the vertical height of a staircase and your own mass, then time yourself walking and running up it. Calculate the energy stored each time and the power developed, and explain why the energy is the same but the power is not.
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 50 kg student climbs 4 m. Energy stored is about (g = 9.81 N/kg):
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.”
Next Smart Experiment
We'll pick an experiment that matches exactly how you're thinking right now.
Share this experiment
Send it to a parent who's looking for a 10-minute kitchen science win.
Ready?
Gravitational Potential Energy
Run the experiment. Find out what really happens.
Full screen — no distractions
Checkout complete lesson on Energy for 9th Grade
Get the full Energy track as a printable PDF — all lessons, worksheets, and answer keys.