The billions of galaxies in the universe are organized into smaller groups of galaxies which in turn belong to larger groups. Janelle wanted to build a scale model comparing the sizes of the major galaxies in the Local Group. The Milky Way and Andromeda are the two largest galaxies in the Local Group. Andromeda has a diameter of about 200,000 light years and the Milky Way has a diameter of about 100,000 light years. Janelle cut out a cardboard disk 3 centimeters in diameter to represent the size of the Milky Way. How large must she make the diameter of the disk representing Andromeda

Astone dropped into a well is heard to strike the water after 8seconds. find the depth of the well if the velocity of sound is 350m/s

As part of an industrial process, air as an ideal gas at 10 bar, 400k expands at steady state through a valve to a pressure of 4 bar. the mass flow rate of air is 0.5 kg/s. the air then passes through a heat exchanger where it is cooled to a temperature of 295k with negligible change in pressure. the valve can be modeled as a throttling process, and kinetic and potential energy effects can be neglected. (a) for a control volume enclosing the valve and heat exchanger and enough of the local surroundings that the heat transfer occurs at the ambient temperature of 295 k, determine the rate of entropy production, in kw/k. (b) if the expansion valve were replaced by an adiabatic turbine operating isentropically, what would be the entropy production? compare the results of parts (a) and (b) and discuss.

Arrange the images in order to show how lake-effect snow occurs.