A pipe carrying an incompressible fluid has a diameter of 100 mm at point 1 and a diameter of 50 mm at point 2. The velocity of the fluid at point 1 is 0.3 m/sec. Most nearly, what is the velocity at point 2

The rocks expand when there hot/warm  and contract when they are cold.

Well i am not very good at this but  i would be guessing 1hope i  

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

Ibelieve the answer above is c but im not sure