Proper velocity Proper velocity In relativity, proper velocity, also known as celerity, is an alternative to velocity for measuring motion. Whereas velocity relative to an observer is distance per unit time where both distance and time are measured by the observer, proper velocity relative to an observer divides observer-measured distance by the time elapsed on the clocks of the traveling object. Proper velocity equals velocity at low speeds. Proper velocity at high speeds, moreover, retains many of the properties that velocity loses in relativity compared with Newtonian theory. For example, proper velocity equals momentum per unit mass at any speed, and therefore
This Is What Rock n' Roll Looks Like been used by Lady Gaga. Ian Drew of "Us Weekly" called the single "shocking" and "electric". Allison Stewart of "The Washington Post" gave "This Is What Rock ‘n’ Roll Looks Like” a mixed review, describing Porcelain Black as a "girl-fronted version of Mötley Crüe circa Dr. Feelgood". Jon Wiederhorn of "Inked" dubbed the song "a euphoric digital feast of raspy melodic vocals, four-to-the-floor beats, and keyboards that buzz like electric guitars." "This Is What Rock n' Roll Looks Like" debuted on the U.S. "Billboard" Hot Dance Club Songs at number forty-six, on the week ending July 18, 2011. The following