advertisement

Chapter 5: Applying Newton's Laws Fx max Example Questions & Problems Fy may (mg, fS μSN, fk μkN, D 41 ρAv 2 ) Example 5.1 The figures show FBDs for an object of mass m. Write the x- and y-components of Newton's second law. Write your equations in terms of the magnitudes of forces F1, F2, ... and any angles defined in the diagram. ma x Fx ma y Fy ma x Fx ma y Fy Example 5.2 The three ropes are tied to a small, very light ring. Two of these ropes are anchored to walls at right angles with the tensions shown in the figure. What are the magnitude and direction of the tension T in the third rope? Example 5.3 The figure shows two 1.00 kg blocks connected by a rope. Assume the rope is massless. The entire assembly is accelerated upward at 3.00 m/s2 by force F. a. What is F? b. What is the tension of rope? Example 5.4 Bonnie and Clyde are sliding a 300 kg bank safe across the floor to their getaway car. The safe slides with a constant speed if Clyde pushes from behind with 385 N of force while Bonnie pulls forward with a rope with 350 N of force. What is the safe's coefficient of kinetic friction on the bank floor? Example 5.5 a. A 0.60 kg bullfrog is on a log tilted 30o above horizontal. How large is the normal force on the log on this bullfrog? b. A 4000 kg truck is moving at constant velocity up a 15° slope. How big is the friction force on the truck?