Answer:

So then the final answer on this case would be:

Explanation:
From the kinetic theory model of gases we know that the velocity rms (speed of gas molecules) is given by:
(1)
Where V represent the velocity
R the constant for ideal gases
T the temperature
M the molecular weight of the gas
We also know from the ideal gas law that 
If we solve for T we got: 
For the initial state we can replace T into the equation (1) and we got:

For the final state we know that :
And the pressure not change , so then the final velocity would be:


So then the final answer on this case would be:

Answer:
t = 200 nm
Explanation:
It is given that,
Wavelength of a light beam is 500 nm
It is reflected constructively from a thin layer of oil having index of refraction 1.25.
The oil floats on the top of water of index of refraction 1.33.
We need to find the minimum thickness of the layer of oil. `
For constructive interference,

m is 1 for minimum thickness
n is refractive index of oil
t is thickness of layer of oil.
So,

So, the minimum thickness of the layer of oil is 200 nm.
Answer:
The bulb with higher temperature(4000 K) will be brighter
Explanation:
From the question we are told that
The color temperature for first bulb is 
The color temperature for second bulb is 
Generally the emission power of black body radiation is mathematically represented as

Where
is the Stefan-Boltzmann constant with a value 
Now for 


At 


Looking at the result we got we see that the emission power for the higher temperature bulb is higher, this means that its power to emit in the visible spectrum range would be higher
So the bulb with higher temperature will be brighter