arydberg

Sorry it was a solution of water and cornstarch.

Tension is the force in the rope. The harder you pull ( if the box is fixed) the more the tension. When a rope breaks it fails under tension. The normal force is the force due to gravity that pushes the box aginst the floor. For a given box the better the wheels or the more slippy the surface the less tension force is required in the rope to move the box.

You can use e^(ix) = cos x + i sin x to prove many trig identities. for example for the double angle formula e^(i2x) = cos 2x + i sin2x (1) but e^(i2x) = e^(ix) * e^(ix) = (cosx + isinx) * ( cosx + isinx) = (cosx)^2 - (sinx)^2 + 2iSinxCosx (2) so setting (1) equal to (2) cos2x + isin2x = (cosx)^2 - (sinx)^2 + 2isinx cosx equating both the real and imaginary parts we get cos 2x = (cosx) ^2 - (sinx)^2 and sin2x = 2sinx cosx

There is another form of this equation. u * v = f^2 However both u and v are measured from the focal point.

I have a question on Maxwell?s equations. I understand that one of the experiments that confirmed Maxwell's equations was performed by John Rowland about 100 years. It consisted of measuring the magnetic field produced by a gold plated disk that had been electrostatically charged and was rotated at a high RPM. The idea was that the rotating disk was supposed to approximate a current moving through a circular loop of wire and thus produce a magnetic field. The problem is that there is a theorem that states that given a right circular magnet placed in a box and rotated about its magnetic axis it is impossible to determine if the magnet is rotating or not solely by measuring the field outside the box In fact there is a uni-polar generator in which one pole of a right circular magnet is placed near to a conducting disk and brushes are used to remove the charge from the center and circumference of the disk. If the magnet is fixed and the disk is spinning a current is produced. The interesting thing is that the exact same current is produced if both the disk AND the magnet are spinning at the same speed! It seems to me that Rowlands experiment is not compatible with the effects described in the preceding paragraph. If the field due to a magnet does not contain any information on weather the magnet is spinning ( About it’s magnetic axis) then the experiment performed by Rowland should not have worked. Some experimenters did indeed claimed that the experiment did not work. Also Richard Feynman in Lectures in Physics has a derivation that indicates that the magnetic field from a current carrying wire is a relativistic consequence of the current carrying electrons traveling near the speed of light. So my question is. Did the Rowland experiment work? I realize that Maxwells equations are a foundation of physics and am not questioning them but I am questioning the Rowland experiment.

I would suggest materials used in capacitors for example Teflon or mica. Teflon is sold in plastics stores in sheets or you could buy Teflon tape for plumbing. For materials check out > http://www.mcmaster.com Al