Answer:
Frequency = 
Wavenumber = 
Energy = 
Energy = 1.4579 eV
Energy = 
Explanation:
As we are given the wavelength = 850 nm
conversion used : 
So, wavelength is 
The relation between frequency and wavelength is shown below as:

Where, c is the speed of light having value = 
So, Frequency is:


Wavenumber is the reciprocal of wavelength.
So,


Also,

where, h is Plank's constant having value as 
So,


Also,

So,


Also,

So,


Answer: the thermal conductivity of the sample is 22.4 W/m . °C
Explanation:
We already know that the thermal conductivity of a material is to be determined by ensuring one-dimensional heat conduction, and by measuring temperatures when steady operating conditions are reached.
ASSUMPTIONS
1. Steady operating conditions exist since the temperature readings do not change with time.
2. Heat losses through lateral surfaces are well insulated, and thus the entire heat generated by the heater is conducted through the samples.
3. The apparatus possess thermal symmetry
ANALYSIS
The electrical power consumed by resistance heater and converted to heat is:
Wₐ = V<em>I</em> = ( 110 V ) ( 0.4 A ) = 44 W
Q = 1/2Wₐ = 1/2 ( 44 A )
Now since only half of the heat generated flows through each samples because of symmetry. Reading the same temperature difference across the same distance in each sample also confirms that the apparatus possess thermal symmetry. The heat transfer area is the area normal to the direction of heat transfer. which is the cross- sectional area of the cylinder in this case; so
A = 1/4πD² = 1/3 × π × ( 0.05 m )² = 0.001963 m²
Now Note that, the temperature drops by 15 degree Celsius within 3 cm in the direction of heat flow, the thermal conductivity of the sample will be
Q = kA ( ΔT/L ) → k = QL / AΔT
k = ( 22 W × 0.03 m ) / (0.001963 m² × 15°C )
k = 22.4 W/m . °C
Step 1:
Start by setting it up with the divisor 8 on the left side and the dividend 27 on the right side like this:
8 ⟌ 2 7
Step 2:
The divisor (8) goes into the first digit of the dividend (2), 0 time(s). Therefore, put 0 on top:
0
8 ⟌ 2 7
Step 3:
Multiply the divisor by the result in the previous step (8 x 0 = 0) and write that answer below the dividend.
0
8 ⟌ 2 7
0
Step 4:
Subtract the result in the previous step from the first digit of the dividend (2 - 0 = 2) and write the answer below.
0
8 ⟌ 2 7
- 0
2
Step 5:
Move down the 2nd digit of the dividend (7) like this:
0
8 ⟌ 2 7
- 0
2 7
Step 6:
The divisor (8) goes into the bottom number (27), 3 time(s). Therefore, put 3 on top:
0 3
8 ⟌ 2 7
- 0
2 7
Step 7:
Multiply the divisor by the result in the previous step (8 x 3 = 24) and write that answer at the bottom:
0 3
8 ⟌ 2 7
- 0
2 7
2 4
Step 8:
Subtract the result in the previous step from the number written above it. (27 - 24 = 3) and write the answer at the bottom.
0 3
8 ⟌ 2 7
- 0
2 7
- 2 4
3
You are done, because there are no more digits to move down from the dividend.
The answer is the top number and the remainder is the bottom number.
Therefore, the answer to 27 divided by 8 calculated using Long Division is:
3