## author: video RGS szu chuang, model lookang

 http://weelookang.blogspot.sg/2015/03/tracker-ping-pong-ball-falling-energy.html the motion is this ping pong ball can be added with self defined function of potential energy PE = m*g*y https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/lookangejss/02_newtonianmechanics_7energyworkpower/trz/pingpongballenergy.trz author: video RGS szu chuang, model lookang
 http://weelookang.blogspot.sg/2015/03/tracker-ping-pong-ball-falling-energy.html the motion is this ping pong ball can be added with self defined function of kinetic energy KE = $\frac{1}{2}m*v^{2}$ https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/lookangejss/02_newtonianmechanics_7energyworkpower/trz/pingpongballenergy.trz author: video RGS szu chuang, model lookang

 http://weelookang.blogspot.sg/2015/03/tracker-ping-pong-ball-falling-energy.html the motion is this ping pong ball can be added with self defined function of total energy TE = PE + KE https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/lookangejss/02_newtonianmechanics_7energyworkpower/trz/pingpongballenergy.trz author: video RGS szu chuang, model lookang
for the easy way to visual the graph, check out this simulation
 set the angle = -90 deg, |v| = 0 at t = 0 and click play.notice the simulation graph and the Tracker of the kinetic energy KE = $\frac{1}{2}mv^{2}$ looks similar with the desired understanding of the simulation is cleaner and easier to understand. http://iwant2study.org/lookangejss/02_newtonianmechanics_2kinematics/ejss_model_projectile/projectile_Simulation.xhtml

i also added 2 models to add coherence to the lessons earlier on modeling

 model m = 2.4x10^3 kg, g = -4.955E0*2, unit mass contact force R1 = 304.5 N/kg, fy = if(t<0.29,g,if(t<0.308,R1+g,g1))*m author: video RGS szu chuang, model lookang

 model m = 2.4x10^3 kg, g = -4.955E0*2, initial velocity y = u0 = 0.1839, initial y displacement y0 = -0.0196, acceleration in y during this stage of motion g1 = -5.080E0*2, final height of model ending h = -0.375, g2 = -4.826E0*2, g3 = -4.710E0*2 author: video RGS szu chuang, model lookang