Alarge bell is hung from a wooden beam so it can swing back and forth with negligible friction. the center of mass of the bell is 0.80 m below the pivot, the bell has mass 30.0 kg , and the moment of inertia of the bell about an axis at the pivot is 15.0 kg⋅m2 . the clapper is a small, 1.8 kg mass attached to one end of a slender rod that has length l and negligible mass. the other end of the rod is attached to the inside of the bell so it can swing freely about the same axis as the bell. what should bethe length l of the clapper rod for the bell to ring silently, thatis, for the period of oscillation for the bell to equal that forthe clapper?

A=v^2/r solve for r hope that  

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