Examlex
The vibrational frequency of an HF molecule is 8.72 × 1013 Hz and the reduced mass of the molecule is 1.589 × 10-27 kg.What is the ground state vibrational energy of an HF molecule? (1 eV = 1.60 × 10-19 J,h = 1.055 × 10-34 J • s,h = 6.626 × 10-34 J • s)
Magic Lanterns
Early projection devices used before the advent of cinema, capable of projecting painted images onto a surface, often used for entertainment and educational purposes.
Motion Toys
Mid-nineteenth century devices that facilitated the viewing of multiple moving images. See also thaumatrope; phenakistoscope; zoetrope; praxinoscope.
Sound on Disc
An early method of providing synchronized sound to silent films using records played in conjunction with the film's projection, before the advent of sound-on-film technology.
Photographic Gun
A device designed in the early history of photography to capture images quickly, resembling the operation of a gun.
Q2: The average SAT verbal score for students
Q10: Is the decay π<sup>0</sup> → μ<sup>+</sup> +
Q15: The angular magnification of a refracting telescope
Q16: In a 35.0-mm single lens reflex camera
Q27: Radium-226 decays into radon-222 plus an alpha
Q32: A rocket is moving at 1/4 the
Q38: X-rays of energy 2.9 × 10<sup>4</sup> eV
Q42: Gradual shifting of a time series over
Q65: A radioactive sample has a half-life of
Q84: In the fission reaction <img src="https://d2lvgg3v3hfg70.cloudfront.net/TB6394/.jpg" alt="In