Right, as you mentioned in the comments, you find
by plugging in the different values of
.
For
, we have



Similarly, for
, you get



Answer:
7.55 km/s
Explanation:
The force of gravity between the Earth and the Hubble Telescope corresponds to the centripetal force that keeps the telescope in uniform circular motion around the Earth:

where
is the gravitational constant
is the mass of the telescope
is the mass of the Earth
is the distance between the telescope and the Earth's centre (given by the sum of the Earth's radius, r, and the telescope altitude, h)
v = ? is the orbital velocity of the Hubble telescope
Re-arranging the equation and substituting numbers, we find the orbital velocity:

I think the question meant to say net force on the box. Since force is a vector, the direction matters. 20N left is negated completely by the 50N right, which means the net force is 50N-20N to the right, 30N.
I believe it would be 2m/s.
A vertical polarizing filter is used on the lens of a camera, they block out the light that is horizontally polarized, so they allow all of the vertically polarized<span> light to pass through.</span>