Falling Baseball.? You drop a baseball from the roof of a tall building. As the ball falls, the air exerts a drag force proportional to the square of the ball’s speed (?f? = Dv?2). (a) In a diagram, show the direction of motion and indicate, with the aid of vectors, all the forces acting on the ball. (b) Apply Newton’s second law and infer from the resulting equation the general properties of the motion. (c) Show that the ball acquires a terminal speed that is as given in Eq. (5.13). (d) Derive the equation for the speed at any time. (?Note?: where defines the hyperbolic tangent.)

Monday, September 11, 2017 BIO3P03: Membrane Potential: Ionic Equilibrium I (Lecture 2) Diffusion Potential • In the example from the ﬁrst lecture, a diffusion potential could be recorded by a voltmeter placed across the two compartments • This potential disappears after concentrations equalize across the barrier (i.e. once the gradient disappears) • Note: The potential tends...