Photoelectric effect
Why can the same light beam eject electrons from one metal but none from another? Which properties of the light determine the photoelectrons' energy?
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PHYSICS · 9 EXPLORATION STEPS
Brownian motion and diffusion
If molecules cannot be seen, what evidence shows that they move randomly?
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▶ Open 3D simulationYOUR EXPLORATION
One step, one new insight.
- 01
Observe moving particles
- 02
Record one position every 30 seconds
- 03
Longer observation, larger mean-square displacement
- 04
Smaller particles, clearer motion
- 05
Higher temperature, stronger motion
- 06
Motion caused by collisions
- 07
Individual observations and statistical results
- 08
Diffusion: a spreading concentration distribution
- 09
Quiz: make motion clearer
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Charging and discharging a capacitor
What does a capacitor actually store? Can a single quantity describe its ability to store charge?
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The relationship between acceleration, force and mass
Without measuring force or acceleration directly, can a paper tape and a few masses reveal the relationship between a, F and m?
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