Suppose you want to know the chemical composition of a distant star. Which piece of information is most useful to you?
A) the wavelengths of spectral lines in the star's spectrum
B) the peak energy of the star's thermal radiation
C) the Doppler shift of the star's spectrum
D) whether the star's spectrum has more emission lines or more absorption lines
A) the wavelengths of spectral lines in the star's spectrum
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In the field, you find an unidentified mineral that is clear, exhibits conchoidal fracture, and can scratch glass. This mineral is most likely:
-gypsum. -calcite. -quartz. -hornblende. -muscovite.
An electron is accelerated from rest through a potential difference. After acceleration the electron has a wavelength of 880 nm. What is the potential difference responsible for the acceleration of the electron?
(h = 6.626 × 10-34 J ? s, melectron = 9.11 × 10-31 kg, e = 1.6 10-19 C) A) 1.9 × 10-6 V B) 1.7 × 10-6 V C) 2.2 × 10-6 V D) 2.5 × 10-6 V
Doubling the momentum of a particle:
a. does not change its relativistic total energy. b. quadruples its relativistic total energy. c. doubles its relativistic total energy. d. requires less of a speed increase as the speed increases.
A wire of diameter d = 1 mm is wrapped around a cylindrical core of radius R = 5 cm and length l = 30 cm to build a solenoid. What is the energy stored in this solenoid when a current I = 0.2 A passes through it?
A) 1.2 × 10-4 J B) 9.6 × 10-4 J C) 4.8 × 10-4 J D) 2.4 × 10-4 J E) 0.6 × 10-4 J