I got no earthly idea! Sorry........
A parsec is a measurement of distance.
Answer:
Explanation:
The force of attraction between 2 masses.
By
vector addition.
In fact, velocity is a vector, with a magnitude intensity, a direction and a verse, so we can't simply do an algebraic sum of the two (or more velocities).
First we need to decompose each velocity on both x- and y-axis (if we are on a 2D-plane), then we should do the algebraic sum of all the components on the x- axis and of all the components on the y-axis, to find the resultants on x- and y-axis. And finally, the magnitude of the resultant will be given by

where Rx and Rx are the resultants on x- and y-axis. The direction of the resultant will be given by

where

is its direction with respect to the x-axis.
Answer:
the distance between adjacent fringes is increased by a factor o 2
Explanation:
To find how the distance between fringes is modified you can use the following formula for the calculation of the distance between fringes:

D: distance to the screen
d: distance between slits
λ: wavelength of the light
if d is decreased by a factor of 2, that is d'=1/2d, you have:

hence, the distance between adjacent fringes is increased by a factor o 2