Physics 6: Optics

Proof required

Link the public repo with the odd-numbered problems of chapters 1–2 written up (a typeset PDF, LaTeX source or notebook), and show the self-check: which answers matched and how you fixed the ones that did not.

What gets checked

• Every lens problem has a ray diagram.
• Sign conventions are stated once and kept.
• Answers are checked against the key, and misses are reworked.

Common mistakes

• Answers copied from the key with no working.
• Wrong units or missing signs.

Powstik Guide

A public write-up of the odd-numbered problems of chapters 1–2, with the self-check shown.

Steps

1. Study the linked course and chapters.
2. Solve the problems on your own first.
3. Check them against the self-check and rework the misses.
4. Typeset the write-up (LaTeX or a notebook) in a public repo.
5. Ask someone who knows physics to check it.

README
Physics 6: Optics, unit 1: Rays, mirrors and lenses
Problems:
Self-check result (matched / reworked):
What I got wrong first and why:

What gets sent back

• No working shown.
• The self-check result is missing.

Resources

What a verifier looks for

• Every lens problem has a ray diagram.
• Sign conventions are stated once and kept.
• Answers are checked against the key, and misses are reworked.
• Is the physics right, not just the final number?

You'll sign in first, then come straight back here.

Proof required

Link the public repo with the odd-numbered problems of chapters 3–4 written up (a typeset PDF, LaTeX source or notebook), and show the self-check: which answers matched and how you fixed the ones that did not.

What gets checked

• Path differences are worked out before any formula.
• Single-slit and grating patterns are told apart.
• Answers are checked against the key, and misses are reworked.

Common mistakes

• Answers copied from the key with no working.
• Wrong units or missing signs.

Powstik Guide

A public write-up of the odd-numbered problems of chapters 3–4, with the self-check shown.

Steps

1. Study the linked course and chapters.
2. Solve the problems on your own first.
3. Check them against the self-check and rework the misses.
4. Typeset the write-up (LaTeX or a notebook) in a public repo.
5. Ask someone who knows physics to check it.

README
Physics 6: Optics, unit 2: Interference and diffraction
Problems:
Self-check result (matched / reworked):
What I got wrong first and why:

What gets sent back

• No working shown.
• The self-check result is missing.

Resources

What a verifier looks for

• Path differences are worked out before any formula.
• Single-slit and grating patterns are told apart.
• Answers are checked against the key, and misses are reworked.
• Is the physics right, not just the final number?

You'll sign in first, then come straight back here.

Proof required

Link the public repo with the method, raw measurements, a photo of the set-up (and the laser's class label, if one is used), the analysis and the result, the result with its uncertainty, and a README that says what you did and what limits the result.

What gets checked

• The spacing's uncertainty comes from D, x and the wavelength on the laser's label (for example 650 ± 10 nm).
• The result is compared with the standard 1.6 µm (or 0.74 µm for a DVD).
• The set-up is safe: no mains power, no laser above class 2, reflections kept away from eyes, no radioactive material, no harmful heat or pressure.

Common mistakes

• A result with no uncertainty.
• Code or data that cannot be rerun from the repo.

Powstik Guide

A measurement of the spacing of the tracks on a CD (or DVD) from the diffraction pattern of a class 2 laser pointer, in a public repo.

Steps

1. Write down what you expect before you start.
2. Shine the pointer straight at the disc through a hole in a card, measure the card-to-disc distance D and the gap x from the hole to each first-order spot, and use d sin θ = mλ with tan θ = x / D.
3. Work out the uncertainty from your own data.
4. Compare with the accepted value and explain any gap.
5. Write the README and ask someone who knows physics to check it.

README
Physics 6: Optics — Measure the track spacing of a CD
What I expected:
Method:
Result (value ± uncertainty):
Accepted value and comparison:
What limits the result:

What gets sent back

• No uncertainty, or one that is guessed.
• An unsafe set-up.

Resources

What a verifier looks for

• The spacing's uncertainty comes from D, x and the wavelength on the laser's label (for example 650 ± 10 nm).
• The result is compared with the standard 1.6 µm (or 0.74 µm for a DVD).
• The set-up is safe: no mains power, no laser above class 2, reflections kept away from eyes, no radioactive material, no harmful heat or pressure.
• The uncertainty is worked out from the data or runs (spread of repeats, instrument limits, fit errors or a range of inputs), not guessed, and it is shown on the result.
• Is the physics right, and could someone rerun it from the repo?

You'll sign in first, then come straight back here.