240 = 0+1/2 (-9.8t
240 = -4.9t
<span>240/-4.9 = t</span><span>
</span>49.0 = t
t= 7.0s
Answer:
High speed optical communication technology
To be able to communicate from the space to the earth and from earth to space is one of the most essential features required during space exploration.
Explanation:
Space exploration involves going into the space, beyond the earth's atmosphere. Landing on other planets and studying their details, going into deeper space beyond the planets to discover new cosmic events or structures is all a part of space exploration.
The key to analyse the studies and observations is being able to communicate the data collected, photos taken etc to the launch centers or space centers on earth. The space centers on earth should also be able to communicate with the persons or the satellites in space.
This is made possible using the optical communication technology which involves the use of optical fibers, lasers etc, since high speeds are more efficient during communication
The electrostatic force between the two ions is 
Explanation:
The electrostatic force between two charged particle is given by Coulomb's law:
where
is the Coulomb's constant
are the two charges
r is the separation between the two charges
In this problem, the ion of sodium has a charge of
while the ion of chlorine has a charge of
And the distance between the two ions is
Substituting, we find the electrostatic force between the two ions:
where the negative sign simply means that the force is attractive, since the two ions have opposite charge.
Learn more about electrostatic force:
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