Aclosed box is filled with dry ice at a temperature of -94.7°c, while the outside temperature is 26.8°c. the box is cubical, measuring 0.285 m on a side, and the thickness of the walls is 3.75 x 10^-2 m. in one day, 3.64 x 10^6 j of heat is conducted through the six walls. find the thermal conductivity of the material from which the box is made.

Explanation:

3.64 x 10⁶ J passes through 6 walls

heat energy passing through 1 wall = 0.606 x 10⁶ J

Surface Area of 1 wall A = .285² = 0.081225 m²

Temperature Difference = T₁ - T₂ = 26.8 + 94.7 = 121.5

Thickness of wall d = 3.75 x 10⁻² m

Rate of heat flow per second R =

=7.01 J per s.

Formula for rate of heat flow

R =

Where K is thermal conductivity.

7.01 =

K = 2.66 X 10⁻² W m⁻¹s⁻¹

when earth is in rotational motion around the sun,it displaces from its place.

when a ball is placed on an inclined surface it does both the rotational and circular motion.

explanation: