1. Gold, has a mass of 19.32g for wach cubic centimeter of volume, is most ductile metal and can be pressed into a thin leaf or drawn out into long fiber.
-If a sample of gold, with a mass of 27.63g is pressed into a leaf of 1.000micometers thickness, what is the area of the leaf?
-If instead the gold is drawn out into cylinder fiber of radius 2.500 micrometers, what is the length of the fiber?
thickness is 1.000 micrometers
density=19.32
mass: 27.63
a) area=(27.63)/((19.32)(1.0x10^-4))=1.43g/cm (of leaf)
b) Volume=AxD=1.43x19.32=27.63
27.63=(pie)r^2L
27.63=(pie)(2.500)^2L=1.408 Length of leaf?
2. Time Standards are now based on atomic clocks. A promising second standard is based on pulsars, which are rotating neutron stars (highly compact stars consisting only of neutrons.) Some rotate at a rate that is highly stable, sending out a radio beacon that sweeps briefly across Earth once with each rotation, like a lighthouse beacon. Pulsar PSR 1937+21 is an example; it rotates once every 1.55780644887275 (plus and minus) 3 ms, where trailing (plus and minus) 3 indicates the uncertainty in the last decimal place. (it does not mean plus and minus 3 ms)
a)