If you stood on Mars and lifted a 15kg pack,you would be pulling with a force greater than...
1 answer:
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Answer:
24445.85 J/s
Explanation:
Area, A = 300 m^2
T = 33° C = 33 + 273 = 306 k
To = 18° C = 18 + 273 = 291 k
emissivity, e = 0.9
Use the Stefan's Boltzman law
Where, e be the energy radiated per unit time, σ be the Stefan's constant, e be the emissivity, T be the temperature of the body and To be the absolute temperature of surroundings.
The value of Stefan's constant, σ = 5.67 x 10^-8 W/m^2k^4
By substituting the values
E = 24445.85 J/s
Answer:
d.The wavelength of light and the size of the aperture
Explanation:
<em>The resolution power of an optical system is the smallest distance between two points that the device can distinguish clearly.</em>
It has the following relationship:
where:
r = minimum resolvable distance
n = numerical aperture
= wavelength of the light used for viewing
From above mathematical equation it is clear that:
- Smaller the wavelength better the resolving power
- Larger the aperture better the resolution
(Note, that smaller the value of "r" the more finer details of the image visible through the device.)
A)
The energy of an x-ray photon used for single dental x-rays is
The energy of a photon is related to its wavelength by the equation
where
is the Planck constant
is the speed of light
is the wavelength
Re-arranging the equation for the wavelength, we find
B)
The energy of an x-ray photon used in microtomography is 2.5 times greater than the energy of the photon used in part A), so its energy is
And so, by using the same formula we used in part A), we can calculate the corresponding wavelength: