In Her Physics Laboratory, Mathilda Shines Electromagnetic Radiation on a Material

question 112

Short Answer

In her physics laboratory, Mathilda shines electromagnetic radiation on a material and collects photoelectric data to determine Planck's constant. She measures a stopping potential of $5.82 \mathrm {~V}$ for radiation of wavelength $100 \mathrm {~nm}$ , and $17.99 \mathrm {~V}$ for radiation of wavelength $50.0 \mathrm {~nm} . \left( 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} , c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$
(a) Using Mathilda's data, what value does she determine for Planck's constant?
(b) What is the work function of the material Mathilda is using, in electron-volts?

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Definitions:

Conscious Mind

The aspect of the mind that is aware of the self, one's surroundings, and one's thoughts, feelings, and experiences at any given moment.

Reality Principle

The goals of the conscious mind, which finds what works in reality.

Structural Model

Sigmund Freud’s model of the mind with three parts: the id (or “it”), the ego (or “I”), and the super-ego (or “above I”).

Freudian Fellows

A term possibly alluding to followers or proponents of Freud's psychoanalytic theories, but not widely recognized or used.