the answer for the question is D. all of the above
Everything starts from spectroscopy. Astronomers only have concentrated information at wavelengths that are emitted from the stars. What they do with this information is to obtain the frequency range of the stars and through spectroscopes they are responsible for dividing the radiation beams and determining the coincidence with the emission of those same waves, of chemical elements. From these observation techniques it is possible to obtain the composition and according to the color, obtaining characteristics such as temperature. The spectrum of stars consists of dark and bright lines called Fraunhofer lines. This spectrum is compared to the spectrum of different elements to find the composition of the stars. This is possible because the elements emit or absorb only specific wavelengths.
Answer:
E. d and O
Explanation:
"Light passing through a single slit forms a diffraction pattern somewhat different from those formed by double slits or diffraction gratings".
According to Huygens’s principle, "for each element of the wavefront in the slit emits wavelets. These are like rays that start out in phase and head in all directions. (Each ray is perpendicular to the wavefront of a wavelet.) Assuming the screen is very far away compared with the size of the slit, rays heading toward a common destination are nearly parallel".
The destructive interference for a single slit is given by:

Where
d is the slit width
is the light's wavelength
is the angle relative to the original direction of the light
m is the order od the minimum
I represent the intensity
When the intensity and the wavelength are incident normally the angular as we can see on the expression above the angular separation just depends of the distance d and the wavelength O.
Because after each impact it loses a fraction of its original energy, because it gets transfered to the floor. this is the reason that a perpetual motion machine is impossible. you cannot have infinite energy, because to perform a task, energy must be spent. hope i helped :3
Answer:
W = 7591.56 J
Explanation:
given,
distance of the box, d = 37 m
Force for pulling the box, F = 217 N
angle of inclination with horizontal,θ = 19°
We know,
Work done is equal to product of force and the displacement.
W = F.d cos θ
W = 217 x 37 x cos 19°
W = 7591.56 J
Hence, the work done to pull the box is equal to W = 7591.56 J