Question $7$

This time you put a nucleus with $5$ protons on the x$-$axis at x$=5\mathrm{.}0$ Angstroms. There

will be a place on the x$-$axis where the total electric field is zero. At what value of x

does this occur?

$-2\mathrm{.}03$ Angstroms

$1\mathrm{.}42$ Angstroms

$1\mathrm{.}14$ Angstroms

$-4\mathrm{.}05$ Angstroms

Question $8(5$ points$)$

Now you have a nucleus with $17$ protons, placed at x$=6\mathrm{.}9$ Angstroms. What what

TWO values of x $($along the x$-$axis$)$ will the total electrostatic potential V be equal to

zero?

$-0\mathrm{.}26$ Angstroms and $0\mathrm{.}19$ Angstroms

$0\mathrm{.}26$ Angstroms and $-0\mathrm{.}19$ Angstroms

$-0\mathrm{.}43$ Angstroms and $0\mathrm{.}38$ Angstroms

$0\mathrm{.}43$ Angstroms and $-0\mathrm{.}38$ Angstroms

Question $9(5$ points$)$

Now you have a nucleus with $17$ protons at x$=6\mathrm{.}5$ Angstroms on the x$-$axis. What is

the value of the electrostatic potential V at a point on the positive y$-$axis, at y$=7\mathrm{.}7$

Angstroms?

$24\mathrm{.}3$ V

$15\mathrm{.}7$ V

$22\mathrm{.}4$ V

$-1\mathrm{.}9$ V

Question $10(5$ points$)$

Now you have a nucleus with $10$ protons at x$=6\mathrm{.}7$ Angstroms on the x$-$axis. How

much work would it take to bring in ANOTHER nucleus with $8$ protons from $1$ m

away and place it at y$=5\mathrm{.}2$ Angstroms on the y$-$axis?

$135\mathrm{.}7$ eV

$56\mathrm{.}8$ eV

$113\mathrm{.}6$ eV

$-22\mathrm{.}1$ eV