2 In the Bohr theory of the hydrogen atom, an electron moves in a
3 circular orbit about a proton, where the radius of the orbit is $r =
5 \Part{a} Find the magnitude of the electric force each exerts on the other.
6 \Part{b} If this force causes the centripetal acceleration of the
7 electron, what is the speed of the electron?
8 \end{problem*} % problem 19.9
20 label.bot("r", (A+C)/2);
24 label.rt("v", draw_velocity(B-(0,1), B, .7*r));
25 draw fullcircle scaled (2*r) shifted A;
46 label.top("F", draw_force(A, B, -r/2));
54 F = k_e \frac{q^2}{r^2}
55 = 8.99\E{9}\U{N$\cdot$m$^2$/C$^2$} \left(\frac{1.60\E{-19}\U{C}}{0.529\E{-10}\U{m}}\right)^2
56 = \ans{8.22\E{-8}\U{N}}
60 Using $F_c = m a_c = m v^2/r$
62 v = \sqrt{\frac{F r}{m}}
63 = \sqrt{\frac{8.24\E{-8}\U{N} \cdot 0.529\E{-10}\U{m}}{9.11\E{-31}\U{kg}}}
64 = \ans{2.19\E{6}\U{m/s}}