Helen is training for the $$hammer thrown$$ in the next Olympics. She grabs one end of a bungee cord $\mathrm{<font><font>(</font></font>}$length$\mathrm{<font><font>1</font></font>}\mathrm{<font><font>.</font></font>}\mathrm{<font><font>2</font></font>}\mathrm{<font><font>0</font></font>}$meters when relaxed$\mathrm{<font><font>)</font></font>}<font><font>,</font></font>$ attaches a $\mathrm{<font><font>7</font></font>}\mathrm{<font><font>.</font></font>}\mathrm{<font><font>0</font></font>}\mathrm{<font><font>0</font></font>}$ kg weight to the other end, and swings the weight around and around in horizontal circles. She gets to making $\mathrm{<font><font>2</font></font>}$ full revolutions per second, and this makes the cord stretch to a length of $\mathrm{<font><font>1</font></font>}\mathrm{<font><font>.</font></font>}\mathrm{<font><font>7</font></font>}\mathrm{<font><font>0</font></font>}$ meters; consider this to be the radius of the weight$$s path. Calculate the spring constant of the cord.