Homework 1. (due 2/11/02)
that the minimum wavelength
of radio waves that can be received at a depth of 10m below the surface of
the sea is of the order of 105 m. The conductivity of sea water
is approximately 4W-1m-1 (
the units are also called Siemens).
For an interesting reading, see
copper rod is 10m long and 6 mm in diameter. Show that its resistance at
100Hz, 1 Mz and 10 GHz is approximately 6 mW, 0.15W
and 15 W
the total force due to the radiation pressure
on a plane which is perpendicular to the direction of the sunlight. The
plane has an area of 1 km2 and the intensity of the sun at the
surface of Earth is 1350 W/m2.
Ti.Sapphire laser has a peak intensity of 1020 W/cm2,
calculate the peak electric field in units of MV/m. What is the electric
field on an electron which is at 1 Bohr radius from the center of the
hydrogen atom? The intensity of
the sun at the surface of Earth is 1350 W/m2. What is the total
power received on the surface of Earth, and compare the number with the
total power received in 1 cm2 of the Ti:Sapphire laser.