HW1 CIV

1) The information on a can of pop indicates that the can contains 460 mL. The mass of a full can of pop is 3.75 lbm while an empty can weights 80.5 lbf. Determine the specific weight, density and specific gravity of pop. Express your results in BG unit. Answer: γ = 107.726 lb/ft 3 , ρ = 3.345 slug/ft 3 and SG = 1.7245. 2) A tank of oil has a mass of 30 slugs. (a) Determine its weight in pounds and in newtons at the earth's surface. (b) What would be its mass (in slug) and its weight (in pound) if located on the moon's surface where the gravitational attraction is approximately one-sixth that at the earth's surface? Answer: (a) 966 lb and 4290 N, (b) 161 lb. 3) A liquid when poured into a graduated cylinder is found to weight 8 N when occupying a volume of 500 mL (milliliters). Determine its specific weight, density, and specific gravity. Answer: γ = 16 kN/m 3 , ρ = 1.63×10 3 kg/m 3 and SG = 1.63. 4) Initially when 1000 mL of water at 10 o C are poured into a glass cylinder the height of the water column is 1000 mm. The water and its container are heated to 70 o C. Assuming no evaporation, what then will be the depth of the water column (h) if the coefficient of thermal expansion for the glass is 3.8×10-6 mm/mm per o C? Let: ρ = 999.7 kg/m 3 for 10 o C and ρ = 977.8 kg/m 3 for 70 o C. Answer: h 70 C = 1021.9 mm. 5) A space 16 mm wide between two large plane surface is filled with SAE 30 Western lubricating oil at 35 o C. What force F is required to drag a very thin plate of 0.4 m 2 area between the surface at a speed v = 0.25 m/s (a) if this plate is equally spaced between the two surface? (b) If t = 5 mm? between the two surface? (b) If t 5 mm? Let: μ at 35 C = 0.81 N s/m 2 Answer: (a) 4.5 N (b) 5.24 N.