Question

3 Google Chrome Web Stor Paycheck PANETID Watch Descend PANETT U SU U U UU UU U US Halliday, Fundamentals of Physics, 10e Grossmont College Physics (PHYC-140-240-241) -ractice Assignment Gradebook ORION Downloadable eTextbook gnment MESSAGE HY INSTRUCTOR FULL SCREEN PRINTER VERSION BACK Chapter 08, Problem 007 The figure shows a thin rod, of length = 3.00 m and negligible mass that can pivot about one end to rotate in a vertical circle. A heavy ball of mass m 8.30 kg is attached to the other end. The rod is pulled aside to angle - 23.0° and released with initial velocity VO-0. As the ball descends to its lowest point, (a) how much work does the gravitational force do on it and (b) what is the change in the gravitational potential energy of the ball Earth system? (c) If the gravitational potentin energy is taken to be zero at the lowest point, what is its value just as the ball is released? Units Units (a) Number (b) Number (c) Number Units s tes P c Police i 2000-2019 John Wiley & Sons, Inc. All Rights Reserved. A Division of she We

Answer 1

(a)The work done by gravitational force is stored as potential energy of the ball is, PE = mgh The height of the pendulum is, h=L(1-cos ) PE = mgl (1-сoso) =(8.30)(9.8) (3.0)(1-сos 23°) = 19.39840566 = 19.4 J (b)From conservation of energy, gravitational potential energy of the ball earth system negative work AU = -PE = -19.4 J (c)The potential energy reference to lowest point is equal to work done by gravitational force is, PE=19.4 J