jermy

Hi, The Center of Mass of a Triangle is a good topic ane here in below m giving a link for your refrence reference: http://physics.tutorcircle.com/rotational-dynamics/center-of-mass.html

Yes the energy is real.For example while lifting an object we put effert (power) that is the energy.So for a particular period of time how much power we used is called the energy. References: http://physics.tutorvista.com/energy.html