Answer:
Les facteurs abiotiques font référence aux éléments physiques et chimiques non vivants de l'écosystème. Les ressources abiotiques proviennent généralement de la lithosphère, de l'atmosphère et de l'hydrosphère.
Explanation:
Answer: of gamma rays with high energies.
Explanation:Gamma-ray bursts are extremely energetic explosions that have been observed in distant galaxies. They are the brightest electromagnetic events known to occur in the universe.
The frequency of the most energetic bursts has been measured at around 3.0×1021 3.0 × 10 21 Hz.
(D) The gravitational force between the astronaut and the asteroid.
Reason :
All the other forces given in the options, except (D), doesn't account for the motion of the astronaut. They are the forces that act between nucleons or atoms and neither of them accounts for an objects motion.
Answer:

Explanation:
The expression which represent the first diffraction minima by a circular aperture is given by
--------eqn 1
The angle through which the first minima is diffracted is given by
---------eqn 2
As
is very small so we can write 
So from eqn 1 and eqn 2 we can write
--------eqn 3
Here
is the position of first maxima D is the distance of screen from the circular aperture d is the diameter of aperture
It is given that diameter of circular aperture is 14.7 cm so 
Now putting all these value in eqn 3

