Consider wave-free laminar condensation on a vertical isothermal plate of length L, providing an average heat transfer coefficient of h L. If the plate is divided into N smaller plates, each of length LN L/N, determine an expression for the ratio of the heat transfer coefficient averaged over the N plates to the heat transfer coeffi- cient averaged over the single plate, .

LECTURE 10 Moment about an axis Moment of a scalar force about any point is to the shortest perpendicular distance To find the moment around an axis (a) We take the dot product of the unit vector of a with (r x F), the cross product of r and F For example, you should set up a problem like so… uax uay uaz rx ry rz Fx Fy Fz ua is the unit vector along the a axis r is the position vector from the a axis to where the force is applied F is the force applied Note: (P x Q) ∙ R = R ∙ (P x Q) LECTURE 11 MOMENT OF A COUPLE A couple is 2 parallel forces with the same magnitude pointing in opposite directions Moment by a couple is defined as Mo = Fd F is the magnitude of the force and d is the perpendicular distance between the