A photocell is a device used to measure the intensity of light. In a certain experiment, when light of wavelength \(630 \mathrm{nm}\) is directed onto the photocell, electrons are emitted at the rate of \(2.6 \times 10^{-12} \mathrm{C} / \mathrm{s}\) (coulombs per second). Assume that each photon that impinges on the photocell emits one electron. How many photons per second are striking the photocell? How much energy per second is the photocell absorbing?

Understanding wavelength conversion is crucial when dealing with light and its interactions with materials, such as in a photocell. The wavelength of light is usually given in nanometers (nm) but can be converted to meters (m) for use in formulas in physics. This conversion is straightforward and is done by multiplying the value in nanometers by the conversion factor of \(10^{-9}\), as one meter is equivalent to \(10^9\) nanometers.

For instance, in the provided exercise, we take the wavelength of \(630 \text{nm}\) and convert it to meters, resulting in \(630 \times 10^{-9} \text{m}\). With the correct units, we're able to apply the relevant formulas for calculations in the photoelectric effect.

The photoelectric effect is a phenomenon in which electrons are emitted from a material's surface when it is exposed to electromagnetic radiation of a certain frequency. This concept is pivotal in understanding how photocells work. When light with sufficient energy strikes the photocell, it causes electrons to be emitted at a rate that depends on the intensity of the light.

In our exercise, the rate of electron emission is tied to the light's wavelength and intensity, allowing us to determine the number of photons hitting the photocell per second. By knowing the charge of each electron, we can calculate the concurrent rate of photons, linking the macroscopic observation of current to the microscopic events involving individual photons and electrons. The core mechanism explained by the photoelectric effect not only applies to photocells but is also essential in understanding various technologies including solar panels and photo detectors.

Planck's constant (\(h\)) is a fundamental constant in quantum mechanics. This constant is crucial for calculations related to the photoelectric effect and other quantum phenomena. It represents a measure of the quantization of energy, showing that energy is transferred in discrete units, or quanta, rather than continuously. The value of Planck's constant is approximately \(6.626 \times 10^{-34} \text{Js}\).

When dealing with photocells, Planck's constant is used to calculate the energy associated with a single photon based on its frequency or wavelength. As shown in our exercise, the energy of a photon (\(E\)) is given by the formula \(E = \frac{hc}{\lambda}\), where \(c\) is the speed of light and \(\lambda\) is the wavelength. Thus, Planck's constant directly assists in determining how much energy per second the photocell is absorbing, highlighting its importance in both theoretical and practical applications in physics.