A rectangular piece of wood floats in water of density 1000kg/m3. Bath oil of density 300kg/m3 is slowly added, forming a layer that does not mix with the water. When the top surface of the oil is at the same level as the top surface of the wood, the ratio of the oil layer thickness to the wood's thickness, x/L = 74 . What is the density of the wood

A bullet of mass m = 26g is fired into a block of mass M = 3.5kg which is hanging from a string of length 1.8m. The bullet becomes embedded in the block and the block swings to a maximum angle of = 37. What was the speed of the bullet before it hit the block?