The suspension bunker is made from plates which are curved to the natural shape which a completely flexible membrane would take if subjected to a full load of coal. This curve may be approximated by a parabola, y = 0.2x2. Determine the weight of coal which the bunker would contain when completely filled. Coal has a specific weight of g = 50 lb>ft3, and assume there is a 20% loss in volume due to air voids. Solve the problem by integration to determine the cross-sectional area of ABC; then use the second theorem of PappusGuldinus to find the volume.

ENGR 232 Dynamic Engineering Systems Lecture 3 Dr. Michael Ryan Agenda • Quick Review – Integrating factor • First Order Differential Equations – Existence – Models • Second Order Differential Equations – Models – Homogeneous equations – Auxiliary equation and its roots – Unique solutions 2 Integrating Factor Method General Case Process a) Write the equation in standard form and identify terms b) Calculate the integrating factor c) Multiply both sides of the equation by the integrating factor. ▯▯ ▯ ▯ ▯▯ + ▯ ▯ ▯ = ▯ ▯ ▯(▯) d)