I Experiments using "optical tweezers" measure the elasticity BIO of individual DNA molecules. For small enough changes in length, the elasticity has the same form as that of a spring. A DNA molecule is anchored at one end, then a force of \(1.5 \mathrm{nN}\) \(\left(1.5 \times 10^{-9} \mathrm{~N}\right)\) pulls on the other end, causing the molecule to stretch by \(5.0 \mathrm{~nm}\left(5.0 \times 10^{-9} \mathrm{~m}\right)\). What is the spring constant of that DNA molecule?