ساينس الصف الأول الاعدادي – الفصل الدراسي الاول ساينس اولي اعدادي ترم اول In This part we will study : The energy changes from one type to another, without losing any of its value. (G.R) The motion of the children’s swing is like that of the pendulum. Because in both of them, the potential and kinetic energies are exchanged without an end and the sum of such energies (the mechanical energy) at any moment is constant. Problem: A moving pendulum has a potential energy 0.8 joule at maximum displacement If the mass of its ball is 0.16 kg and acceleration due to gravity is 1 O m/s2 • Calculate: a. The height (h) of the pendulum’s ball at maximum displacement. b. The kinetic energy of the ball at such point (B). Solution a. Object weight= object mass x acceleration due to gravity = 0.16 x 10 =1.6 Newton The potential energy at the maximum displacement = weight x height 0.8 = 1.6 x height So; height (maximum displacement)= 0.8/1.6 = 0.5 m. b. The kinetic energy of the ball at the maximum displacement (B) is zero . لمتابعة مستر احمد الباشا وكل ما يخص الساينس : جروب الفيس بوك http://bit.ly/2Of1mcN صفحة الفيس بوك http://bit.ly/2Gq5xMo بالتوفيق مستر احمد الباشا