Frequency calculating from wavelength

For any ultrasound of frequency v, the longitudinal wavelength 7i at the surface can be calculated from Equation 19.1, in which a is the surface tension of the liquid and p is the density of the liquid. 

Self-Test 1.1A Calculate the wavelengths of the light from traffic signals as they change. Assume that the lights emit the following frequencies green, 5.75 x 1014 Hz yellow, 5.15 x 1014 Hz red, 4.27 X 1014 Hz. 

Calculate the wavelength or frequency of light from the relation Xv = c (Example 1.1). 

Spectroscopy Drug compounds absorb visible, infrared, and UV radiation at frequencies that are characteristic of the compounds. Quantitative measurements can be calculated from the absorbance readings at specific frequencies or wavelengths. 

In the previous example, we have calculated the plasma frequency for metallic Na from the free electron density N. In Table 4.1, the measnred cutoff wavelengths, Xp, for different alkali metals are listed together with their free electron densities. The relatively good agreement between the experimental values of Xp and those calculated from Equation (4.20), within the ideal metal model, should be noted. It can also be observed that the N values range from abont 10 to about 10 cm leading to... 

What energy is associated with a 1H nmr transition The magnitude of this energy may be calculated from the relationship between energy and wavelength (frequency) of the absorbed radiation (Section 9-4). That is,... 

Self-Test 1.1 A Calculate the wavelengths of the light from traffic signals as they change (use the frequencies given above). 

Dayhoff [50] suggested that one might measure a rest mass of photon by designing a low-frequency oscillator from an inductor-capacitor (LC) network. The expected frequency can be calculated from Maxwell s equations, and this may be used to give an effective wavelength for photons of that frequency. He claimed that one would have a measure of the dispersion relationship at low frequencies. Williams [51] calculated the effective capacitance of a spherical capacitor using Proca equations. This calculation can then be generalized to any capacitor with the result that a capacitor has an additional term that is quadratic in the area of the plates of the capacitor. However, this term is not exactly the one that Dayhoff referred to. But it seems to be a very close description of it. One can add two identical capacitors C in parallel and obtain the result... 

In the frequency-domain, the experimentally measured quantities are the frequency- (w) and wavelength- (X) dependent phase shift (0m(X,a>)) and demodulation factor (MnXX, )). For any assumed decay model (equation 1), these values are calculated from the sine (S(X,o>)) and cosine (C(X,w)) Fourier transforms. If we assume the decay kinetics are described by a simple sum of exponential decay times we have (24) ... 

Raman vibrational frequencies and intensities for both complexes 5 and 7 are compared in Table II. The relative Raman scattering intensities were calculated from the differential cross sections. For their evaluation we used the wavelength of 613.33 nm (105). Polarizabilities were calculated in the limit of a static perturbation. 

Note The values in Tables 2-1 and 2-2 are expressed as wavelengths and wavenumbers in air. The difference between Av (air) and Av (vacuum) is usually less than 1cm-1 and can be ignored in Raman spectroscopy. When molecular constants are calculated from absolute Raman frequencies, Av (air) must be converted to Av (vacuum). 

For FT-Raman spectrometers, an equivalent one-point calibration is more reliable because interferometers are less prone to mechanical errors. Nearly all interferometer designs include a well-defined reference wavelength (often a He-Ne laser at 632.8 nm), which is used to control data acquisition. In addition, observed FT frequencies are calculated from a large number of individual measurements, so minor mechanical jitter and random timing errors are averaged out. Provided the laser and reference frequencies are known accurately, an observed FT-Raman frequency is quite accurate, and the one-point calibration is usually adequate. 

The speed of sound in dry air at 20°C is 343.5 m s, and the frequency of the sound from the middle C note on a piano is 261.6 s (according to the American standard pitch scale). Calculate the wavelength of this sound and the time it will take to travel 30.0 m across a concert hall. 

A piano tuner uses a tuning fork that emits sound with a frequency of 440 s. Calculate the wavelength of the sound from this tuning fork and the time the sound takes to travel 10.0 m across a large room. Take the speed of sound in air to be 343 m s. ... 

Table 5 shows the experimental specific refractivities, K X) = n(l) l]/ p, and the average polarizability as calculated from equation (1) at a number of frequencies for liquid and vapour phases. The values of the specific refractivity of the vapour have been obtained from the Cauchy dispersion formula of Zeiss and Meath.39 In this paper the authors assess the results of a number of experimental determinations of the refractive index of water vapour and its variation with frequency. Even after some normalization of the data to harmonize the absolute values from different determinations there is a one or two percent spread of results at any one wavelength. Extrapolation of the renormalized data for five independent sets of data leads to zero frequency values of K(7.) within the range (2.985-3.013) x 10-4 m3 kg 1, giving, via equation (1), LL — 9.63 0.10 au. Extrapolation of the earlier refractive index data of Cuthbertson and Cuthbertson40 by Russell and Spackman41 from 8 values of frequency between 0.068 and 0.095 au, leads to a zero frequency value, of y.i, 1,(0) = 9.83 au. While the considerable variation between the raw experimental data reported in different determinations is cause for some uncertainty, it appears that the most convincing analysis to date is that of... 

The blue color of the sky results from the scattering of sunlight by air molecules. The blue light has a frequency of about 7.5 X 10 Hz. (a) Calculate the wavelength, in nm, associated with this radiation, and (b) calculate the energy, in joules, of a single photon associated with this frequency. 

Calculate the frequency (Hz) and wavelength (nm) of the emitted photon when an electron drops from the M = 4 to the n = 2 level in a hydrogen atom. 

We see from Fig. 26a (solid line 1) that the loss spectrum, calculated for our model with the same parameters, as chosen above (Table IX), exhibits resonance lines at the frequencies v < 50 cm-1. At v < 20 cm-1 the calculated solid loss curve 1, becoming nonresonant, coincides with the nonresonant dashed curve 2 calculated from Eqs. (72)-(74) with cfit = 2.35. Both loss s" curves 1 and 2 decrease linearly with v (in the log-log plot) in the interval from 50 to 0.1 cm-1 For further decrease of frequency the empirical dependence (72) exhibits a minimum at v about 0.1 cm-1 (viz, in the millimeter wavelength region). Near this minimum and at lower frequencies, our molecular model should not be applied. 

Now, we can calculate the wavelength and frequency from this energy. he... 

Time-resolved emission spectra Although there have been several attempts to simplify the characterisation of the SR process, the determination of time-resolved emission spectra (TRES) is certainly the most general and most precise way to quantitatively describe the solvent response. The time-resolved emission spectra are usually determined by spectral reconstruction [96, 97, 106]. The time-resolved emission spectrum at a given time t is calculated from the wavelength dependent time-resolved decays by relative normalization to the steady-state spectrum [107]. By fitting the TRES at different times t by the empirical log-normal function, the emission maximum frequencies i (t) (or 2(t) see Fig. 6.26) and the total Stokes-shift Ac (or A2) are usually derived [106]. Since c(t) contains both information about the polarity (Ac) and the viscosity of the reported environment, the spectral shift c(t) may be normalized to the total shift Ac. The resulting correlation functions C(t) (Eq. (7)) describe the time course of the solvent response and allow for comparison of the SR-kinetic and, thus, of relative micro-viscosities, reported from environments of different polarities [96, 97, 106, 108, 109, 116, 117, 122]... 

The procedure consists of scanning the frequency response of a loaded resonator, whose unloaded characteristics are known. The permittivity and dissipation factor are calculated from the shift in peak frequency (or wavelength) and the Q-factor. 

Solve The frequency, v, is calculated from the given wavelength, as shown in Sample Exercise 6.2 ... 

As discussed in Section 5.10. the lifethnes calculated from the phase and modulation at a single frequency are only a arait values. The heterogMems decay of DAPI in water illustrates this effect. For an observaticm wavelength of470 nm and a modulation frequency of 100 MHz,... 

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