Free form questions (forms in parentheses):

• The howitzer (A-D): recoil velocity = 16 m/s, spring constant = 44,200 N/m
• The car crash (E-F): After the collision, the heavier car was travelling 9.5 m/s; the lighter 11.0 m/s. Before the collision, the heavier car was travelling 16 m/s.
• The diagonal pole (A-D): F_v = mg = 353 N, F_h = T = 306 N
• The horizontal pole (E-F): F_v = T_v = F_h = T_h = 588 N
• The blimp (A-B): You need 2.7 blimps, which means that you really need 3.
• The coffee can (C-D): 475 ball-bearings are right at the critical limit.
• The iceberg (E-F): The iceberg has a density of 917 kg/m³.