Answer:
B) convection
Explanation:
Heat convection is the result of heat conducting between fluid or gas and solid, and is closely related to the flow of the fluid and condition of the interface.
Answer:
Explanation:
Conduction of heat through a thick layer is governed by the following relation
Q = KA( T₂ -T₁ ) / d
K is thermal conductivity of medium ( it is earth here ) , A is surface area though which heat conducts and T₂ -T₁ is temperature difference and d is thickness of medium through which heat conducts.
k = 8 units
A = surface area= 2πrL
= 2x 3.14 x 2/12 x 100
= 104.67 ft²
T₂ -T₁ = 70 - 42
= 28 F
d = thickness
= 30 /12 ft
= 2.5 ft
Putting the given values here
Q =
= 9378.4 Btu per hour.
Velocity = 90 km/h = 25 m/s
Drag coefficient, Cd = 2D/Density of air*Frontal area*sqr. velocity
Substituting,
Cd = (2*230)/(1.164*1.25*1.65*25^2) = 0.3066
A force can be considered a push or pull
hope this helps :)