Answer:
1791 secs ≈ 29.85 minutes
Explanation:
( Initial temperature of slab ) T1 = 300° C
temperature of water ( Ts ) = 25°C
T2 ( final temp of slab ) = 50°C
distance between slab and water jet = 25 mm
<u>Determine how long it will take to reach T2</u>
First calculate the thermal diffusivity
∝ = 50 / ( 7800 * 480 ) = 1.34 * 10^-5 m^2/s
<u>next express Temp as a function of time </u>
T( 25 mm , t ) = 50°C
next calculate the time required for the slab to reach 50°C at a distance of 25mm
attached below is the remaining part of the detailed solution
Answer:
1. 
2. 
Explanation:
1.
Given:
- height of the window pane,

- width of the window pane,

- thickness of the pane,

- thermal conductivity of the glass pane,

- temperature of the inner surface,

- temperature of the outer surface,

<u>According to the Fourier's law the rate of heat transfer is given as:</u>

here:
A = area through which the heat transfer occurs = 
dT = temperature difference across the thickness of the surface = 
dx = t = thickness normal to the surface = 


2.
- air spacing between two glass panes,

- area of each glass pane,

- thermal conductivity of air,

- temperature difference between the surfaces,

<u>Assuming layered transfer of heat through the air and the air between the glasses is always still:</u>



Answer:
(a) dynamic viscosity = 
(b) kinematic viscosity = 
Explanation:
We have given temperature T = 288.15 K
Density 
According to Sutherland's Formula dynamic viscosity is given by
, here
μ = dynamic viscosity in (Pa·s) at input temperature T,
= reference viscosity in(Pa·s) at reference temperature T0,
T = input temperature in kelvin,
= reference temperature in kelvin,
C = Sutherland's constant for the gaseous material in question here C =120

= 291.15
when T = 288.15 K
For kinematic viscosity :


Answer:
Welding, carpentry, masonry, construction worker, barber
Explanation: