An observation of the red shift of galaxies suggests that the universe is
a.
expanding.
c.
reversing.
b.
contracting.
d.
stagnant.

An observation of the red shift of galaxies suggests that the universe is expanding. The answer is letter A. .  It means that bodies farther away from Earth were moving away faster. The Hubble’s constant is the ratio of distance to redshift equal to 170 kilometers per second per light year of distance.

this is poiselle's equation from fluid mechanic in physics. mech eng

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.