Suppose the entire population of the world gathers in one spot and, at the sounding of a prearranged signal, everyone jumps up. While all the people are in the air, does Earth gain momentum in the opposite direction? a) No; the inertial mass of Earth is so large that the planet’s change in motion is imperceptible.
b) Yes; because of its much larger inertial mass, however, the change in momentum of Earth is much less than that of all the jumping people.
c) Yes; Earth recoils, like a rifle firing a bullet, with a change in momentum equal to and opposite that of the people.
d) It depends.

Velocity is the speed of an object in a certain direction so you'd need to know speed and direction

Following the american gauge wire standards ,the larger gauge number, the slimmer the wire and thus the smaller current carrying capacity it can have.then both statements would be incorrect, as they are saying the opposite of what it is actually is.(smaller gauge numbers have thicker wires and can carry more current)

Stars are born within the clouds of dust and scattered throughout most galaxies. a familiar example of such as a dust cloud is the orion nebula. turbulence deep within these clouds gives rise to knots with sufficient mass that the gas and dust can begin to collapse under its own gravitational attraction. as the cloud collapses, the material at the center begins to heat up. known as a protostar, it is this hot core at the heart of the collapsing cloud that will one day become a star. three-dimensional computer models of star formation predict that the spinning clouds of collapsing gas and dust may break up into two or three blobs; this would explain why the majority the stars in the milky way are paired or in groups of multiple stars.therefor, i would say the answer is: dust and gases contract.i hope this ! < 3