## What is a Planck curve?

The energy density of a black body between λ and λ + dλ is the energy E=hc/λ of a mode times the density of states for photons, times the probability that the mode is occupied. This is Planck’s famous formula for the energy density of a black body.

## What does Planck’s law describe?

Planck’s law describes the electromagnetic radiation emitted by a black body in thermal equilibrium at a definite temperature. The law is named after Max Planck, who originally proposed it in 1900. It is a pioneering result of modern physics and quantum theory.

**What assumption did Max Planck have to make in order to explain the observed blackbody radiation spectrum?**

To explain the blackbody radiation curve, Planck assumed that the exchange of energy between radiation and cavity walls takes place only in discrete quanta of energy.

### What is Planck quantum principle?

According to Planck’s quantum theory, Different atoms and molecules can emit or absorb energy in discrete quantities only. The smallest amount of energy that can be emitted or absorbed in the form of electromagnetic radiation is known as quantum.

### What did Planck discover?

Max Planck was a German theoretical physicist who discovered the quantum of action, now known as Planck’s constant, h, in 1900. This work laid the foundation for quantum theory, which won him the Nobel Prize for Physics in 1918.

**What is the Planck frequency?**

Due to mass–energy equivalence, the Planck constant also relates mass to frequency. = 6.62607015×10−34 J⋅Hz−1. that was proportional to the frequency of its associated electromagnetic wave.

#### How did Planck contribute to the atomic theory?

Planck’s work in thermodynamics led to the formulations of his quantum theory. Planck called the packets of energy quanta and he was able to determine that the energy of each quantum is equal to the frequency of the radiation multiplied by a universal constant that he derived, now known as Planck’s constant.

#### Who was Planck and how did he discover his constant?

German physicist Max Planck introduced the constant in 1900 in his accurate formulation of the distribution of the radiation emitted by a perfect absorber of radiant energy, called a blackbody.

**Why did Planck suggest his theory?**

Planck’s work in thermodynamics led to the formulations of his quantum theory. To explain the colors of hot glowing matter, he proposed that energy is radiated in very minute and discrete quantized amounts or packets, rather than in a continuous unbroken wave.

## What is AP Human Geography Population?

AP Human Geography Population. Author of Essay on the Principle of Population (1798) who claimed that population grows at an exponential rate while food production increases arithmetically, and thereby that, eventually, population growth would outpace food production.

## What does standard of living mean AP Human Geography?

AP Human Geography Population. a level of material comfort in terms of goods and services available to someone or some group; “they enjoyed the highest standard of living in the country”; “the lower the standard of living the easier it is to introduce an autocratic production system.

**What is a population distribution curve?**

A model used in population geography to show the age and sex distribution of a particular population. The difference between the number of births and number of deaths within a particular country. A type of curve which shows the growth of a variable in terms of another variable, often expressed as units of time.

### What is demographic transition AP Human Geography?

AP Human Geography Population. Demographic transition model a sequence of demographic changes in which a country moves from high birth and death rates to low birth and death rates through time.