8. (a) Since 1 cm3= 10–6m3, the magnitude of the current density vector is Jnev==FHGIKJ××=×−−−87010160 10470 10654 1061937....mCm/sA/m32chch(b) Although the total surface area of Earth is 42πRE(that of a sphere), the area to be used in a computation of how many protons in an approximately unidirectional beam (the solar wind) will be captured by Earth is its projected area. In other words, for the beam, the
This is the end of the preview. Sign up
access the rest of the document.