Quote of the Day: "The shortest distance between two points is under construction." -- Bill Sanderson Objectives: The student will compute higher order derivatives. The student will be able to compute velocity and acceleration for a given displacement function. 1. Collect Homework. 2. Higher-Order Derivatives (Second derivatives, …) To determine the second derivative, take the derivative of the first derivative. The notation for the second derivative: Examples: 3. Distance, Velocity, and Acceleration A. Problem: You make a roundtrip from Winchester to Harrisonburg, a distance of 60 miles one way (actually, any distance will work in this problem). If you travel down at 30 m.p.h., and return at 60 m.p.h., what was your average m.p.h. over the whole trip? Use the following table to help answer the problem: B. Problem: There is a single path up a mountain in Shenandoah National Park. A mountaineer starts up at 7:00 AM and arrives at the top at 7:00 PM. She stays there overnight. The next morning, she starts back down at 7:00 AM and arrives at the bottom at 7:00 PM. On both days, she travels at varying speeds – enjoying the scenery, stopping for lunch, smelling the roses… What is the probability that there was a spot on the trail that she passed at exactly the same time on both days? Hint: Draw a Displacement – Time graph! Answer: It is 100%. Look at the Displacement-Time Graph – it doesn't matter how long she takes to come back down, there must be at least one place where the descent curve must cross the ascent curve. C. Given a displacement curve, s = f(t) The velocity is defined to be the change in the displacement divided by the change in time, or in other words, the first derivative of displacement with respect to time. It measures how fast you are going. The acceleration is defined to be the change in the velocity divided by the change in time, or in other words, the derivative of velocity with respect to time. When you press down on the accelerator in your car, you are changing the velocity. The jerk is a sudden change in acceleration. When a ride in a car is jerky, it is not that the accelerations involved are necessarily large but that the changes in acceleration are abrupt. Jerk is what spills your soft drink. The derivative responsible for jerk is the third derivative of position. Example: 4. Assignment: p. 197 (3, 29, 30, 33, 41, 44, 45, 47, 67) |