black_stallion

Okay, in the Escape Velocity Equation, with the usual notations, v2=2gR2/r + (v02-2gR) a few articles like www.math.binghamton.edu/erik/teaching/02-separable.pdf and http://www.uv.es/EBR...5000_17_84.htmlgive the following explanation: ... ... ...(implying that v0>=√2gR) That raises a few doubts in my mind: (1)Does the term 2gR2/r become zero? (2) If the answer to (1) is yes(i.e. 2gR2/r=0), then how come v0 is allowed a value equal to √2gR?(since, substituting v0=√2gR in the original equation(i.e. v2=2gR2/r + (v02-2gR)) will yield v=0(which is obviously not desired if a particle has to escape the Earth) (3)If the answer to (1) is no(i.e. 2gR2/r>0), then what is the fuss about (v02-2gR) being required to be positive at all? I mean, if it were negative, does it affect the original equation so much that v becomes zero? Question (3) could be rephrased in this way: If (v02-2gR) becomes negative, does it always become less than (2gR2/r)?(thus giving v as negative)

Hi! What is the maximum temperature(or heat) that a typical sunmica/formica sheet used on table tops can tolerate without damaging(its upper layer)? In many households, I've noticed that a hot vessel just off the stove is rarely placed directly over the tabletop; a stand or some cloth is placed between both the surfaces(to prevent apparent 'damage' to the table). The general consensus around my city seems that the kind of mica used in tabletops doesn't have much thermal resistance. Is this true?