Question

On a part-time job, you are asked to bring a cylindrical iron rod of density 7800 kg/m3 , length 82.0 cm and diameter 2.75 cm from a storage room to a machinist. calculate the weight of the rod, w. the acceleration due to gravity, g = 9.81 m/s2 .

Answer 1

Weight of the rod = mg= mass * acceleration due to gravity. We seek to solve for its mass since acc due to gravity is known. Mass = Density * Volume. Volume of a cylindrical rod = Î * r^2 * h. Where height=length= 82.0cm = 0.82m and radius which is half the diameter = (2.75/2) = 1.375cm = 0.01375m. So the volume = 3.1428 * (0.01375)^2 * 0.82 = 4.87241.So volume = 4.87241. Hence Mass = 4.87241 * 7800 = 38004.7 And weight = 38004.7 * 9.81 = 372827.06N