Which statement describes solstices? A. They occur when the Sun reaches its highest or lowest point in the sky.
B. They affect the amount of sunlight in the Southern Hemisphere in May.
C. They contribute to the cycling of winters all year long in the Northern Hemisphere.
D. They increase the amount of rays from the Sun directly received in the Southern Hemisphere.

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.

What elements are found in the inner and out core of the earth? the correct layers of earth's interior from the top to the center? what is the unwanted material that is removed from a mine called? how much stronger is an earthquake that registers 5 on the richter as opposed to 2? what occurs at a convergence plate boundary? the majority of the the earth's rock what is the most common element found in the earth's crust? what element is found in pyrite that contributes to acid mine drainage? why must mining companies post bond prior to permitting? how are bacteria being used in treating effluent from mines? what is a problem of acid mine drainage in rivers and soils? what do tectonic plates move on? why is gold smelting so damaging? how are artesian wells formed? where is dammed water colder than the river it flows into? what is one of the problems of uncontained aqueducts? what is the largest use of industrial water? underground sand and gravel formations that can store water? what type of water test measure acidity? which type of water test for cloudiness from suspended solids? what water test measures the amount of calcium and magnesium? these are all problems of coal power plants all of the following are advantages of riparian lands along rivers what type of water would be the warmest and have the least amount of dissolved oxygen? the zone of aeration is

Awater balloon launcher uses an elastic band with a spring constant of 115 n/m to use thee launcher you stretch thee band back with a balloon n it the water balloons have a mass of 1.3 kg a) if you stretch the band by 0.8 m, what elastic force will the band exert? b) with the band stretched 0.8 m, how much elastic potential energy is stored in the spring? c) if you release the band, it pushes forward. what is the kinetic energy of the balloon when it reaches the natural length of the band? d) what is the speed of the balloon when it reaches the natural length of the band?