Physics, 26.11.2019 03:31 estrella7777

Solar heating of a house is much more efficient if there is a way to store the thermal energy collected during the day to warm the house at night. suppose one solar-heated home utilizes a concrete slab of area 14 m2 and 21 cm thick.
a. if the density of concrete is 2400 kg/m3, what is the mass of the slab?7100kg
b. the slab is exposed to sunlight and absorbs energy at a rate of 1.9 ×107j/h for 10 h. if it begins the day at 25 ∘c and has a specific heat of 750 j/(kg⋅k), what is its temperature at sunset?
c. model the concrete slab as being surrounded on both sides (contact area 28 m2) with a 1.7-m-thick layer of air in contact with a surface that is 5.0 ∘c cooler than the concrete. at sunset, what is the rate at which the concrete loses thermal energy by conduction through the air layer?
d. model the concrete slab as having a surface area of 24 m2 and surrounded by an environment 5.0 ∘c cooler than the concrete. if its emissivity is 0.92, what is the rate at which the concrete loses thermal energy by radiation at sunset?
i need b, c, and d! show all work.

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