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Natasha2012 [34]
3 years ago
14

A carpenter builds an exterior house wall with a layer of wood 3.1 cm thick on the outside and a layer of Styrofoam insulation 2

.3 cm thick on the inside wall surface. The wood has k = 0.080W/(m⋅K), and the Styrofoam has k = 0.010 W/(m⋅K). The interior surface temperature is 19.0 ∘C, and the exterior surface temperature is -15.0 ∘C.A.)What is the temperature at the plane where the wood meets the Styrofoam?
B.)What is the rate of heat flow per square meter through this wall?
Physics
1 answer:
lapo4ka [179]3 years ago
6 0

Answer: T = -0.213°c

Heat flow = 38.2 w/m²

Explanation:

given data:

Wood = 0.031m thick

Styrofoam = 0.023m thick

Wood = k ( 0.080W/m.k)

Styrofoam = k (0.010W/m.k)

Temperature of wood = -15°c

Temperature of styrofoam = 19°c

(a) heat flow in wood and styrofoam must be equal

KAdT/ L = KAdT/ L

0.080 * A * ( T - ( -15) ) / 0.031 = 0.010 * A * ( T - ( 19°c) ) / 0.023

T = -0.213°c

(b) heat flow

H = KAdT / L

H = 0.080 * A * ( -0.213°c - ( -15°c) ) / 0.031

= 38.2 w/m²

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8 0
3 years ago
In Millikan's oil drop experiment an oil drop is at rest between two large plates separated by 1.3 cm when the potential differe
sweet-ann [11.9K]

Answer:

Mass of the oil drop, m=3.01\times 10^{-15}\ kg

Explanation:

Potential difference between the plates, V = 400 V

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m=\dfrac{qE}{g}

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E is the electric field, E=\dfrac{V}{d}=\dfrac{400}{0.013}=30769.23\ V/m

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3 years ago
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Answer:

Explanation:

Since the wires attract each other , the direction of current will be same in both the wires .

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The point will lie between the two wires  as current is in the same direction.

Let at y = y , the neutral point lies

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Serga [27]
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A theory changes based on new observations and testing.

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