Question

12.1 On a part-time job, you are asked to bring a cylindrical iron rod of length 85.8 cm and diameter 2.85 cm from a storage room to a machinist. Will you need a cart? (To answer, calculate the weight of the rod.)

Answer 1

We know, the density (P) of iron = 7860 kg/m^3 the diameter d of the cylindrical iron rod = 2.85m the constant pi = 3.14 the volume (v) of the cylinder = pi r^2h As lcm = 10^-2m radius (R) = 2.85/2 times 10^-2 m = 1.425 times 10^-2m h = length = 85.8cm = 85.8 times 10^-2m so the required mass m = pv = p(pi r^2 h) = (7860 kg/m^3) (pi) (1.425 times 10^-2 m)^2 (85.8 times 10^-2m) = 4.30 kg weight of the rod w = mg = (4.30 kg) (9.8 m/s^2) w = 4.20N so, we don't need cart