Explanation:
When Michelson-Morley apparatus is turned through
then position of two mirrors will be changed. The resultant path difference will be as follows.

Formula for change in fringe shift is as follows.
n = 

v = 
According to the given data change in fringe is n = 1. The data is Michelson and Morley experiment is as follows.
l = 11 m
c =
m/s
Hence, putting the given values into the above formula as follows.
v = 
= 
= 
Thus, we can conclude that velocity deduced is
.
Answer:
Technician A is right. The situation will happens even with only two bulbs in series
Explanation:
We must take into account that
1.- All electric device need its nominal voltage to operate
2.-Any and all electric device means an electric load for the source in terms of equation that means any device will implies a drop voltage of V = I*R ( I the flows current and R the resistance of the device)
3.-Nominal voltage for bulbs are specify for houses voltages you find between fase and neutral wires for instance in Venezuela 120 (v).
4.-In a imaginary circuit of only one bulb, the nominal voltage will be applied and the bulb will operates correctly, but when you add another bulb (in series) the nominal voltage will split between the two bulbs ( we could find a situation such as the first bulb work properly but the second one does not). The voltage split according to Ohms law (in such way that the sum of voltage between the terminal of the first bulb plus the voltage at terminals of the second one are equal to nominal voltage.
For that reason all the bulbs are connected in parallel in wich case all of them will operate with the common voltage
For this case we have that by definition:

Where,
- <em>m: mass of the object
</em>
- <em>a: acceleration of the object
</em>
- <em>F: summation of forces
</em>
We have then:

Then, by clearing the acceleration we have:

Substituting values we have:

Answer:
The acceleration of the box is equal to:

Answer:
The radius is decreasing at 4 mm/s
Explanation:
The volume of a sphere is:
So, when the volume is 972π mm^3 the radius r is:
r = 9mm
Now, the change rate is given by the derivative:
Where: dV/dt = -324π mm^2/s
r = 9mm
Solving for dr/dt:
dr/dt = -4mm/s
Answer:
ºC
Explanation:
First, let's write the energy balance over the duct:

It says that the energy that goes out from the duct (which is in enthalpy of the mass flow) must be equals to the energy that enters in the same way plus the heat that is added to the air. Decompose the enthalpies to the mass flow and specific enthalpies:

The enthalpy change can be calculated as Cp multiplied by the difference of temperature because it is supposed that the pressure drop is not significant.

So, let's isolate
:

The Cp of the air at 27ºC is 1007
(Taken from Keenan, Chao, Keyes, “Gas Tables”, Wiley, 1985.); and the only two unknown are
and Q.
Q can be found knowing that the heat flux is 600W/m2, which is a rate of heat to transfer area; so if we know the transfer area, we could know the heat added.
The heat transfer area is the inner surface area of the duct, which can be found as the perimeter of the cross section multiplied by the length of the duct:
Perimeter:

Surface area:

Then, the heat Q is:

Finally, find the exit temperature:

=27.0000077 ºC
The temperature change so little because:
- The mass flow is so big compared to the heat flux.
- The transfer area is so little, a bigger length would be required.