The parallax angle for the red supergiant star betelgeuse has been measured using hipparcos to be 4.51 ± 0.80 mas (milliarcseconds). (g. m. harper et al 2017, aj, 154,11), a. find the distance to betelgeuse in units parsecs including uncertainty (which will be asymmetric, so you need to compute + and-uncertainties b. convert the optimal distance you computed in parsecs in part (a) into light-years; c. determine the distance modulus for betelgeuse (you may ignore uncertainty). separately) and round to the right number of significant figures. au. keep the correct number of significant figures. using clear english prose, explain why result makes sense (i certainly hope it d. betelgeuse has a mean v magnitude of m-0.45. what is its mean luminosity in solar luminosities? again, ignore uncertainty for now. hint: the sun's absolute vluminosity is~4.83

Chapter 23, problem 075 the figure shows a geiger counter, a device used to detect ionizing radiation (radiation that causes ionization of atoms). the counter consists of a thin, positively charged central wire surrounded by a concentric, circular, conducting cylindrical shell with an equal negative charge. thus, a strong radial electric field is set up inside the shell. the shell contains a low-pressure inert gas. a particle of radiation entering the device through the shell wall ionizes a few of the gas atoms. the resulting free electrons (e) are drawn to the positive wire. however, the electric field is so intense that, between collisions with gas atoms, the free electrons gain energy sufficient to ionize these atoms also. more free electrons are thereby created, and the process is repeated until the electrons reach the wire. the resulting "avalanche" of electrons is collected by the wire, generating a signal that is used to record the passage of the original particle of radiation. suppose the radius of the central wire is 24 âµm, the inner radius of the shell 2.3 cm, and the length of the shell 14 cm. if the electric field at the shell's inner wall is 2.8 ă— 104 n/c, what is the total positive charge on the central wire?

Two polarizers are oriented at 40∘ to each other and plane-polarized light is incident on them. if only 16 percent of the light gets through both of them, what was the initial polarization direction of the incident light?

1. a camcorder has a power rating of 19 watts. if the output voltage from its battery is 7 volts, what current does it use?answer units 2. a 1.5m wire carries a 6 a current when a potential difference of 57 v is applied. what is the resistance of the wire? your