Dear John, Just thinking about this gives me a headache!
Cheers, Pat Naughtin CAMS Geelong, Australia on 2002-11-20 01.37, John Nichols at [EMAIL PROTECTED] wrote: > It is not that the equation is F=ma, but that it is the > > sum of the forces = ma. > > Now it would have had velocity so the damping factor would have come into > play as it contacted Newton's head. The displacement from the point of > impact till it was stopped brings the stiffness into play. > > So assuming that it feel 1 metre (What else would God pick for such an > important experiment) and that g is 9.81 in that place on the earth then > > it would have taken the square root of 2/9.81 as the fall time being 0.45 > seconds, give or take a thousands of a second. > > it would have been travelling with a velocity of 4.4 m/s give or take a > smidgen. > > given a stiffness of the apple of 0.1 GPa and of the human as 1.0 kPa > ignoring the increasing stiffness as bone comes into play, probably taking > it up to about 10 GPa, limestone is 40 GPa so I am assuming 0.25 of that. > > The displacement into the head was about 1 mm. Which means the apple > actually fell 1.001 so we can repeat the whole thing and find out that in > reality it penetrated 1.001 mm and so on on so forth. until some one points > out that it was actually 39.37 inches falling with a velocity of > 778.5 inches per George with a travel time of 0.1 Georges ( I have > allowed one Imperial George to equal 4.5 seconds. ) > > Now I stop because the maths is beyond my University level. > > Of course if there had been a stiff breeze no..................... > > John Nichols > > > At 02:27 AM 19-11-2002, you wrote: >> At 8:57 +1100 02/11/19, Pat Naughtin wrote: >>> As a side issue, you might like to compare this last average with the apple >>> that is supposed to have fallen on Sir Isaac Newton's head in his garden at >>> Woolsthorpe. Presumably Newton's apple had a weight of one newton, and we >>> can safely assume that the acceleration due to gravity was about the same as >>> now (say 9.8 m/s^2). Using the formula F = ma, it follows that the mass of >>> Newton's apple was m = F/m = 1 � 9.8 = 102 grams. It follows that Isaac >>> Newton's original apple (allowing certain assumptions) was quite small. >> >> Indeed we were quite lucky: imangine that the famous apple was huge, say >> 500 g, Isaac Newton could well have been knocked out... >> >> Louis > > John Nichols BE, Ph.D. (Newcastle), MIE (Aust), Chartered Professional > Engineer > Assistant Professor > Texas A&M University > Department of Construction Science > Langford AC > Rm: A414 MD 3137 > College Station, TX 77843-3137 > > Electronic mail: [EMAIL PROTECTED] > Telephone: 979 845 6541 > Facsimile: 979 862 1572 > ----------------------------------------------------------------- > a fronte praecipitium a tergo lupi > > in front a precipice, behind a wolf > ----------------------------------------------------------------- >
