Laboratory experiments here on earth have determined that each element in the periodic table emits photons only at certain wavelengths. these photons are apparent to astronomers as either emission or absorption lines in the spectrum of an astronomical object, like stars in galaxies. astronomers can, by measuring the position of these spectral lines, determine which elements are present in the star itself or along the line of sight. when astronomers perform this analysis, they note that for most astronomical bodies, the observed spectral lines are all shifted to longer (redder) wavelengths. this is known as cosmological redshift and is analogous to the doppler redshift. what does this redshift indicate to us about the universe in general?
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Physics, 22.06.2019 00:30
Ablock of steel has a density of 0.29lbs per cubic inch. if the block has dimensions of 1 inch by 1 inch by 3 inches, what is its weight? a. 0.29lbs b. 0.58lbs c. 0.87lbs d. 1lbs
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Physics, 22.06.2019 10:00
Suppose a wheel with a tire mounted on it is rotating at the constant rate of 2.15 times a second. a tack is stuck in the tire at a distance of 0.373 m from the rotation axis. noting that for every rotation the tack travels one circumference (a) find the tack's tangential speed. (b) what is the tacks radial acceleration?
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Physics, 22.06.2019 11:00
The dot diagram represents the motion of the motorcycle as it moves from left to right
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Physics, 22.06.2019 11:30
A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?
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Laboratory experiments here on earth have determined that each element in the periodic table emits p...
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