I took "Statics and Dynamics" during summer school at college in 1980. An eighth week intensive summer school program. All the professor's work was on a black board. White chalk only. (1) I enjoyed the pace of your presentation; AND, (2) I enjoyed your graphics.. Thank you.
Now I understand how to use this method properly. When I checked on other RU-vid video, they tend to neglect the work done by gravity when working on inclined plane problems like this. So I'm getting confused. Anyway thank you very much!
I used mechanical energy, where the top had 0 KE and the bottom had 0 PE Ei+Wf=Ef where Wf is work done by friction 0.5mVi^2+mgHi+(-fk)=0.5mVf^2+mgHf where the initial kinetic energy and the final potential energy are 0, and fk is friction. Masses cancel, multiply 2 to the left hand side and square root it Sqrt(2[9.81*0.5-9.81cos(30°)*0.15])=Vf=2.92 m/s
You can get the same answer using law of conservation of energy potential energy initial + kinetic energy initial - non conservative force = potential energy final + Kinetic energy final
