An observation of the red shift of galaxies suggests that the universe is
a.
expanding.<...
Physics, 03.01.2020 14:31 hannahbaak
An observation of the red shift of galaxies suggests that the universe is
a.
expanding.
c.
reversing.
b.
contracting.
d.
stagnant.
Answers: 2
Physics, 21.06.2019 21:00, jjxt126
A150 w lamp emits light of wavelength 590 nm uniformly in all directions. what is the photon flux (photons per unit area per unit time) on a small screen at a distance 2.3 m from the lamp? assume the photons are uniformly distributed over the surface of a sphere of radius 2.3 m.
Answers: 2
Physics, 21.06.2019 22:30, elijahdecent6070
Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. provide a plausible explanation for this situation (with supporting calculations) by considering a room whose air temperature is maintained at 20â°c throughout the year, while the walls of the room are nominally at 27â°c and 14â°c in the summer and winter, respectively. the exposed surface of a person in the room may be assumed to be at a temperature of 32â°c throughout the year and to have an emissivity of 0.90. the coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 w/m2 â‹…â‹… k. what is the ratio of the thermal resistance due to convection to the thermal resistance due to radiation in the summer? what is the ratio of thermal resistances in the winter
Answers: 1
Physics, 22.06.2019 11:10, ladybee05
Avolcano erupts next to a grassland area in a valley. a. describe three ways in which material released by the volcano could impact the grassland area. b. describe three ways in which the grassland ecosystem could recover after a volcanic eruption.
Answers: 3
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