標題:

phy archimedesprinciple

發問:

1. a polythene rod of length 0.5m floats upright in water(a) given that the densities of polythene and water are 920 1000kg/m^3 respectively,what is the length of the rod immersed in water?(b)if the rod floats in another liquid with 0.4m of its length under the liquid surface, what is the density 2. an object... 顯示更多 1. a polythene rod of length 0.5m floats upright in water (a) given that the densities of polythene and water are 920 1000kg/m^3 respectively,what is the length of the rod immersed in water? (b)if the rod floats in another liquid with 0.4m of its length under the liquid surface, what is the density 2. an object of mass 100kg is tied to the bottom of a pond with a light chain. if the tension in the chain is 200N,what is the mass of water displaced by the oobject? 3. a balloon of volume 2000m^3 is filled with hot air of density 0.95kg/m^3, if the mass of the fabric and basket is 200kg and that of the pilot is 75kg. what is the maximum load that can be arried when operating in air of density 1.25kg/m^3

最佳解答:

此文章來自奇摩知識+如有不便請留言告知

1.(a) Let L be the length of rod immersed in water. Mass of water displaced = 1000.L.A where A is the cross-sectional area of the rod. Upthrust = 1000LAg, where g is the acceleration due to gravity Hence at equilibrium, 1000LAg = 0.5A.(920)g i.e. L = 0.5 x 920/1000 m = 0.46 m (b) Mass of liquid displaced = 0.4Ap, where p is the liquid density Hence, 0.4Apg = 0.5A(920)g i.e. p = 0.5/0.4 x 920 kg/m3 = 1150 kg/m3 2. Upthrust = (100g + 200) N = 1200 N where g is the acceleration due to gravity, taken to be 10 m/s^2 Weight of water displaced = 1200 N (Archimedes Principle) Mass of water displaced = 1200/g kg = 120 kg 3. Volume of air displaced = 2000 m^3 hence, upthrust = 2000 x 1.25g N = 2500g N Total weight of hot air, balloon and pilot = (2000 x 0.95g + 200g + 75g) N = 2175g N Therefore, max weight of load to be carried = (2500g - 2175g) N = 325g N Mass of max load = 325 kg

其他解答:7638E7481407D16B
arrow
arrow

    omckyyo 發表在 痞客邦 留言(0) 人氣()