1. The problem statement, all variables and given/known data A tunnel of length L = 141 m, height H = 6.9 m high, and width 6.0 m (with a flat roof) is to be constructed at distance d = 60 m beneath the ground. The tunnel roof is to be supported entirely by square steel columns, each with a cross-sectional area of 960 cm2. The mass of 1.0 cm3 of the ground material is 2.8 g What is the total weight of the ground material the columns must support? I have attached the picture that goes with this problem; hopefully it works! 2. Relevant equations Volume = L(w)(d) = (141m)(6m)(60m) = 50760m^3 1.0cm^3 = .01m^3 2.8g = .0028kg Total weight = Volume * .0028kg * 9.8m/s^2 3. The attempt at a solution Total weight = Volume * .0028kg * 9.8m/s^2 I know that this is wrong but I can't come up with anything else that makes sense and could use some help! Thank you in advance!