Mechanical energy mechanical energy of the colliding objects has been converted into an equal amount of heat. Thus, the total energy of the system remains unchanged though the mechanical energy of the system has reduced. A satellite of mass formula_4 at a distance formula_5 from the centre of Earth possesses both kinetic energy, formula_6, (by virtue of its motion) and gravitational potential energy, formula_7, (by virtue of its position within the Earth’s gravitational field; Earth's mass is formula_8). Hence, mechanical energy formula_9 of a satellite is given by If the satellite is in circular orbit, the energy conservation equation can be further
Feathers: The Evolution of a Natural Miracle news magazine "Maclean's", Brian Bethune praised Hanson's storytelling, writing, "For all the intriguing science, what really livens up Hanson's passionate discussion of his 'natural miracle' are the stories he tells." Laurence A. Marschall, a physics professor at Gettysburg College, wrote in a review published in the magazine "Natural History", "In sum, "Feathers" is an impressive blend of beauty, form, and function." Frances C. James, in a review published in "The Condor", described the book as "scholarly and enjoyable", commenting that "Hanson has worked hard to summarize the science behind our current understanding of the form and function of feathers, their