4] a student has a large number of coins of different diameters , all made of the same metal. she wishes to find the density of the metal by a method involving placing the coin in water. a] state the formula needed to calculate the density. b] describe how the measurements of the required quantities are carried out. c] state one precaution taken when carrying out the measurements in [b] to ensure that the result is as accurate as possible. 5] a student wishes to determine the density of a small, irregularly shaped stone. a] with the aid of a labelled diagram, describe an experiment to determine the volume of the stone. b] state the other quantity, apart from the volume, that must be measured in order to determine the density. [ii] state the formula that is used to calculate the density. c] the student now wishes to determine the volume of a small, irregularly shaped piece of wood that floats in water. he notices that a small lead weight tied to the wood makes it sink in water. describe how the student can adapt the experiment in [a] to determine the volume of the wood. you may draw a diagram. 6b] the density of aluminium is 2.70g/cubic meter. the thickness of a rectangular sheet of aluminium foil varies, but is much less than 1mm. a sheet wishes to find the average thickness. she obtains the following measurements. mass of sheet= 60.7g length of sheet=50.0 cm width of sheet=30.0 cm calculate the students values for; [i] the volume of the sheet. [ii] the average thickness of the sheet. c] another student, provided with a means of cutting the sheet , decides to find it's average thickness using a single measuring instrument . assume the surfaces of the sheet are perfectly smooth. [i] name a measuring instrument she could use. [ii] describe the procedure she should follow to obtain an accurate value of the average thickness of the sheet. details of how to read the instrument are not required. 7]the tank is 51m long and 20m wide. the sea-water in the tank is 11m deep and has a density of 1030kg/cubic meter. a] calculate the mass of water in the tank. b] the pressure at point M, halfway down the large viewing panel, is 60kpa more than atmospheric pressure. calculate the depth of M below the surface of the water. c] the viewing panel is 32.8m wide and 8.3m high. calculate the outward force of the water on the panel. assume that the pressure at M is the average pressure on the whole panel.