11. Instead, the equivalent weight  ( EW ) and material thickness are used to describe most commercially available membranes. 12. The contest calls for two flights within two weeks with a pilot and two passengers, or the equivalent weight . 13. It is a 4-seat car so should be within its limits carrying the equivalent weight  of 4 heavy adults. 14. Since I didn't have one in my book bag that day, I decided to build one using materials of equivalent weights . 15. A bottle of Coca-cola with Lemon is known to be 3 times as sour as the equivalent weight  of real lemons. 16. The USSBS believed that Bomber Command's heavy bombs-4, 000 lb " cookies "-were more effective than an equivalent weight  of smaller bombs. 17. Equivalent weights  were originally determined by experiment, but ( insofar as they are still used ) are now derived from molar masses.18. Adding a plane of a certain weight to the atmosphere is just like adding an equivalent weight  of air to the atmosphere. 19. The equivalent weight  or epoxide number is used to calculate the amount of co-reactant ( hardener ) to use when curing epoxy resins. 20. These boats must carry what is known as " the 18th man ", a passenger or the equivalent weight  up to 100 kg.