Thermal Storage Solar heating of a house is much more efficient if there is a wa

Question

Thermal Storage 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 12 m2 and 26 cm thick.

Part B is exposed to sunlight and absorbs en rate J/h ror at a of 1.3 x10 10 h. If it begins the day at 25 Cand has a specific heat of 750 kg K), what is its temperature at sunset? The slab Exp s your answer to two significant figures and de approp Value Units Submit My Answers Give Part C Model the concrete slab as being surrounded on both sides (contact area 24 m wrh a 1.8-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? Express your answer to two significant figures and include appropriate units Value Units Submi My Answers Give Up Part D Modal the concroto slab as having a surface aroa of 24 m and surrounded by an onvironmont 5.0 C lar than the concreto. Ifits ity is 0.94, what is the rate at which the ncreta loses thermal energy by radiation at sunset? Express your answer to two significant figures and include appropriate units. Value Units

Explanation / Answer

B)We know that,

Q = m C (T2 - T1)

(T2 - T1) = Q/ m C

m = density x volume

m = 2400 x 12 x 0.26 = 7488 kg

Q = P x t = 1.3 x 10^7 J/h x 10h = 1.3 x 10^8 J

T2 - T1 = 1.3 x 10^8/7488 x 880 = 19.73 deg C

T2 = T1 + 19.73 = 25 + 19.73 = 44.73 deg C

Hence, T2 = 44.73 deg C

C)we know that,

Q/t = k A (Th - Tc)/d

Q/t = 0.002 x 24 (44.73 - 5)/1.8 = 1.06 W

Hence, Q/t =1.06 W

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.