Why do you think McDonald Observatory is located in the Davis Mountains of west Texas? a
Observatories must be built on mountains.
b
It was placed there to attract visitors to the observatory.
c
It is one of the darkest locations in the United States and that allows astronomers to have a clearer view of the sky.
d
It is operated by the University of Texas at Austin.

b

Explanation:

you discarded the ones that weren't the best possible choices because it'll get less reviews and ratings.

your final design covers each requirements due to going over the details of what's needed and not. due to this you also have a better design that'll get lots of views and ratings.

ek = (m.v2) / 2

v - velocity of system after the collision

m = m1 + m2

ek = (m1 + m2) v2/2

ek = (200 + 250) 2,32/2 = 450*5,29/2 = 1190,25 j

by: nicholas dooley