1. Engineering Analysis for Portable Hockey Goal March 3, 2004 W.A.R. Andrew ClarkeSean Moseley Tyler LoweAdam Waddle Nick Maser Davison Wilson ME 4182-C Professor Harvey Lipkin

2. Weight Using a camping chair as an example Material: Aluminum Pole Diameter (do): 3/4 inches Pole Thickness (t): 1/16 inches Cross-sectional area: A = 0.071 in^2

3. Weight (cont.) Total Length of Hockey Goal: 660 in (55 feet) Volume: V = 46.9 in^3 Material Density: r = 0.0976 lbm/in^3 (2.7 g/cm^3) Mass: M = r* V = 4.58 lbm (2.08 kg) Neglecting weight of the hinges and net

4. Spring Analysis (opening) Opening time of 1 second x = 3 feet (half the width of the goal) a = x /t^2 = 3.0 ft/s^2 F opening = m * a = 4.58 lbm * 3.0 ft/s^2 = 13.74 lbf

5. Spring Analysis (closing) D x = 10.75 inches F closing = F opening = k* D x Therefore the spring constant k = 1.28 lbf/in