A block of wood has these dimensions: length = 0.45m, width…

A block of wood has these dimensions: length = 0.45m, width = 0.25m, height = 0.15m. It has a density of 850kg/m^3. The block is floating in a tub of water. What is the mass of the block of wood? How much extra mass would have to placed on top of the block so that the top surface of the block is even with the surface of the water?

The world’s heaviest insect, New Zealand’s Giant Weta, has a…

The world’s heaviest insect, New Zealand’s Giant Weta, has a mass of 0.07kg. Suppose a Weta (which we will consider to be a point mass) is sitting on the outer rim of a disc of radius 0.4m and of mass = 0.85kg. Both are rotating at a rate of 2.7rad/sec. The intrepid Weta walks inward towards the center of the disk and stops at a point 0.04m from the center.  What is the initial angular momentum of the system? What is the final angular velocity of the system? What condition is necessary for conservation of angular momentum?