This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Homework #3 Due midnight Sunday October 9. 1. Use the ideas of inertia and Newtons 1st and 2nd laws to explain why offensive lineman in football are huge but running backs are not. 2. What is the net force on the blocking sled in Fig. 5-6c? What direction does it point? What is the net force in Fig. 5-6b? 3. The diagram on the next page shows graphs of speed (top) and water drag force (bottom) during the breaststroke cycle.. (Hint: Note that the lower graph is not the net force on the swimmer. The net force is the forward propulsive force provided by the swimmer minus the illustrated drag force.) (a) Consider the top graph first. At what point in the cycle is the positive acceleration largest? (Describe in terms of what the swimmer is doing.) What is the swimmer doing when the acceleration is large and negative? (b) Estimate quantitatively the maximum (positive) acceleration. Hint: Read v and t from the top graph. ....
View Full Document