1. What is the Photoelectric Kinetic Energy Equation?

The photoelectric effect equation describes the kinetic energy of electrons emitted from a material when exposed to electromagnetic radiation. This fundamental equation demonstrates the particle nature of light and was crucial in the development of quantum mechanics.

2. How Does the Calculator Work?

The calculator uses the photoelectric effect equation:

Where:

• \( KE \) — Kinetic energy of emitted electron (J)
• \( h \) — Planck's constant (6.62607015 × 10⁻³⁴ J·s)
• \( \nu \) — Frequency of incident radiation (Hz)
• \( \phi \) — Work function of the material (J)

Explanation: The equation shows that electron kinetic energy depends linearly on radiation frequency and is independent of radiation intensity. Electrons are only emitted when photon energy exceeds the work function.

3. Importance of Photoelectric Effect

Details: The photoelectric effect provided experimental evidence for quantum theory, earned Einstein the Nobel Prize, and has practical applications in solar cells, photodiodes, and image sensors.

4. Using the Calculator

Tips: Enter Planck's constant in J·s (default value provided), frequency in Hz, and work function in J. All values must be positive, and frequency must be sufficient to overcome the work function.

5. Frequently Asked Questions (FAQ)

Q1: What is the work function?
A: The work function is the minimum energy needed to remove an electron from a material's surface. It varies by material and typically ranges from 2-6 eV for metals.

Q2: Why is kinetic energy zero below threshold frequency?
A: Below threshold frequency, individual photons don't have enough energy to overcome the work function, so no electrons are emitted regardless of light intensity.

Q3: What are typical work function values?
A: Common values: Cesium (1.95 eV), Potassium (2.30 eV), Sodium (2.75 eV), Copper (4.65 eV), Platinum (5.65 eV).

Q4: How does intensity affect the photoelectric effect?
A: Higher intensity increases the number of emitted electrons but not their kinetic energy. Energy depends only on frequency.

Q5: What is the significance of this equation?
A: It demonstrated light's particle nature, validated quantum theory, and explained why classical wave theory failed to predict experimental results.