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Please show the work for these problems. Answers are provided for 1a, 1c, and 1d

ID: 2035041 • Letter: P

Question

Please show the work for these problems. Answers are provided for 1a, 1c, and 1d.

1A) An object has a surface area of 0.005 m2. The force exerted by air pressure (at atmospheric conditions) on the object is about? Answer: 500 N 1B) Given that at sea level air is usually at a pressure of around 100 Pa what force is the atmosphere exerting on any given 1 cm2 of our body? 1C) Cork has a density of 0.24 g/cm3 What fraction is exposed above the water if the cork is floating on the surface of the water? Answer: 76% 1D) The mass of a person in air is 70.0 kg and his apparent mass when submerged in water to be 2.00 kg. Calculate the density of the person. (Note- significant digits matter here) Answer: 1.029 x 103 kg m-1

Explanation / Answer

1A) Force = pressure * area

atmospheric pressure = 1.01325*10^5

F = 1.01325*10^5*0.005 = 506.625 N

1B) F = 100*10^3*1*10^-4

= 10 N

1C) Density = 0.24 g/cm3

density of water = 1 g/cm3

fraction exposed above water = (1 - 0.24 ) / 1 * 100

= 76%

1D) m - mapparent = pliquid V

where V = voume of object

70 - 2 = pliquid V

68 = 1000 *V

V = 0.068

density of person = mass/volume = 70/0.068 = 1029 .4 kg/m3