Response:

Clarification:
If
-
,
represent the temperatures of gases and liquids in Kelvins,
and
denote the thicknesses of the gas layer and steel slab in meters,
,
are the convection coefficients for gas and liquid in
,
represents the contact resistance in
,
- and
signify thermal conductivities of gas and steel in
,
then: part(a):

by employing known values:
part(b): Utilizing the rate equation:
the surface temperature is 
and 
Correspondingly


The temperature profile is depicted in the image provided
Answer: 592.37m
Explanation:
Person D is represented by the blue line.
The total displacement is calculated by subtracting the initial position from the final position. Starting at (0,0), the path consists of moving down two blocks, then right six blocks, followed by moving up four blocks, and finally left one block.
Here, I consider the positive direction of the x-axis to the right and the positive direction of the y-axis as upward.
Thus, the new coordinates will be, with B representing a block:
P =(6*B - 1*B, -2*B + 4*B) = (5*B, 2*B)
Given that B = 110m
P = (550m, 220m)
The displacement corresponds to the length of the vector, since the change from the initial position (0,0) to P is simply P:
P = √(550^2 + 220^2) = 592.37m
Each washer has a mass of 0.0049 kg.
The total mass of two washers amounts to 0.0098 kg.
The mass for three washers is 0.0147 kg.
The total mass for four washers is 0.0196 kg.