Question: How much energy would be released if Earth were annihilated by collision with an anti-Earth?
this energy will power the sun for 8.826*10^7 years.
During the annihilation of matter and antimatter whole mass converts to energy. mass of earth made of matter and antimatter is equal.
this energy will power the sun for 8.826×107 years.
The rest energy of many short-lived particles cannot be measured directly but must be inferred from the measured momenta and known rest energies of the decay products. Consider the meson, which decays by the reaction. Calculate the rest energy of the meson given that the oppositely directed momenta of the created pions each have a magnitude 358.3 MeV. See Table 44-4 for the rest energies of the pions.
Use Wien’s law (see Problem 37) to answer the following questions: (a) The cosmic background radiation peaks in intensity at a wavelength of. To what temperature does this correspond? (b) About after the big bang, the universe became transparent to electromagnetic radiation. Its temperature then was . What was the wavelength at which the background radiation was then most intense?
Because the apparent recessional speeds of galaxies and quasars at great distances are close to the speed of light, the relativistic Doppler shift formula (Eq.37-31) must be used. The shift is reported as fractional red shift
(a)Show that, in terms of, the recessional speed parameter is given by
(b) A quasar in 1987 has . Calculate its speed parameter.
(c) Find the distance to the quasar, assuming that Hubble’s law is valid to these distances.
Question: Due to the presence everywhere of the cosmic background radiation, the minimum possible temperature of a gas in interstellar or intergalactic space is not 0 K but 2.7 K. This implies that a significant fraction of the molecules in space that can be in a low-level excited state may, in fact, be so. Subsequent de-excitation would lead to the emission of radiation that could be detected. Consider a (hypothetical) molecule with just one possible excited state. (a) What would the excitation energy have to be for 25% of the molecules to be in the excited state? (Hint: See Eq. 40-29.) (b) What would be the wavelength of the photon emitted in a transition back to the ground state?
The wavelength at which a thermal radiator at temperature radiates electromagnetic waves most intensely is given by Wien’s law: localid="1663130298382" (a) Show that the energy of a photon corresponding to that wavelength can be computed from
(b) At what minimum temperature can this photon create an electron-positron pair(as discussed in Module 21-3)?
94% of StudySmarter users get better grades.Sign up for free