The choices are confusing. Air, oil, and alcohol are fluids at any reasonable temperature. Dry cement is not.
Answer: 31.33 degrees
Explanation:
The diffraction angles 
when we have a slit divided into 
parts are obtained by the following equation:
(1)
Where:
is the width of the slit
is the wavelength of the light
is an integer different from zero.
Now, the first-order diffraction angle is given when 
, hence equation (1) becomes:
(2)
Now we have to find the value of 
:
(3)
We know:
In addition we are told the diffraction grating has 5000 slits per mm, this means:
Substituting the known values in (3):
<u>Finally:</u>
>>>This is the first-order diffraction angle
The cost of boiling 500cm3 of water using the 3kW kettle is 1.35 P.
<h3>
Cost of electricity for 3 kW kettle</h3>
The cost is calculated as follows;
1 unit = 9p /kWh
Total energy consumed by 3 kW kettle, E = P x t
where;
- P is power (kW)
- t is time in (hr)
E = 3 kW x (3 mins/60 mins/hr)
E = 0.15 kWh
Energy cost = 9 p/kWh x 0.15 kWh = 1.35 P
Thus, the cost of boiling 500cm3 of water using the 3kW kettle is 1.35 P.
Learn more about energy cost here: brainly.com/question/13795167
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A. Illustrates how a theory becomes a law
They can change because the law of conservation of energy allows it to happen, for example when you are sitting, your body is at a potential energy state, meaning you are inert, you are not moving, but when you get up and suddenly start walking or running, that energy is converted to kinetic energy, meaning that you are moving and can be changed back into potential energy if all of a sudden you stop running or walking to rest or sit down. This is just an example of how energy can are transferred multiple ways
