posted by Ri .
As a comet swings around the Sun, ice on the comet's surface vaporizes, releasing trapped dust
particles and ions. The ions, because they are electrically charged, are forced by the electrically charged
solar wind into a straight ion trail that points radially away from the Sun. The electrically neutral dust
particles are pushed radially outward from the Sun by the radiation force on them from sunlight.
Assume the dust particles are spherical, have density 3.5x103kg m-3, and are totally absorbing.
What radius must a particle be traveling (around the sun) in order to, instead of circling around the Sun,
follow a straight path?