Design a test that separates the pendulum from the spring
Three steps, the way the exam actually works: work through the lab, write down your own measurements, then answer a 6-point free response. What you recorded goes to the grader with your writing, so a conclusion that does not follow from your own numbers will cost you the point — exactly as it would with a real reader.
Predict before you look
- One of these two oscillators gets its restoring force from gravity and the other from a spring. Which is which?
- If a restoring force is supplied by gravity, and the inertia resisting it also scales with mass, what happens to the mass dependence?
Nothing to submit here — these are to think through, so the prediction below is an informed one rather than a guess.
Commit to an answer now. It is not graded and being wrong costs nothing — the point is to have something specific to reconcile against once you have the data.
Answer every prediction to unlock the lab. A sentence is enough.
Run the investigation
Predictions first
The procedure and the simulation unlock once you have committed above. Observing before predicting is how a wrong intuition survives a lab intact.
Record what you measured
These are your numbers, not ours. The grader sees them, so your conclusions have to follow from what you actually recorded.
| Pendulum period · Earth, 1.0 kg | s |
|---|---|
| Spring period · Earth, 1.0 kg | s |
| Pendulum period · Earth, 3.0 kg | s |
| Spring period · Earth, 3.0 kg | s |
| Pendulum period · Moon, 1.0 kg | s |
| Spring period · Moon, 1.0 kg | s |
Answer the free response
Two oscillators run side by side in this simulation: a simple pendulum and a mass on a spring. (a) Using your data, state which oscillator's period changed when you changed the mass and which did not, and justify both results from the governing equations. (b) Using your data, state which oscillator's period changed when you moved to the Moon and which did not, and justify both results. (c) A classmate concludes from part (b) that "a mass on a spring would not oscillate at all in orbit, because there is no gravity to pull it back." Evaluate that claim. (d) The pendulum equation you used is an approximation. State the condition under which it holds, and describe the specific change you would make to this simulation to test whether the approximation breaks down — including what you would expect to observe if it does.
Sign in to have this graded and saved to your progress.