Answer:
The value is 
Explanation:
From the question we are told that
The amount of power delivered is 
The time taken is 
The wavelength is 
Generally the energy delivered is mathematically represented as
Where 
is the Planck's constant with value 
c is the speed of light with value 
So
=>
A light year is a measurement of distance that is used in the space. It is the distance that a light traveled for 1 year on Earth or 365 days on Earth at a speed of 3 x 10^8 meters per second. To convert the units from light year to the SI unit meters, we simply make use of the definition of the unit. We do as follows:
18.9 light years ( 365 days / 1 light year ) ( 24 h / 1 day ) ( 3600 s / 1h ) ( 3 x 10^8 m/s) = 1.79 x 10^17 meters
Therefore, 18.9 light years is equal to 1.79 x 10^17 meters.
Labels that belong in regions X, Y, Z;
B) X: Back of hand, for force
Y: Thumb, for velocity
Z: Palm of hand, for force
