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ccaramel Nov16-07 04:10 PM

DNA Electric Force Problem
 
A molecule of DNA (deoxyribonucleic acid) is 2.09 Ám long. The ends of the molecule become singly ionized -- negative on one end, positive on the other. The helical molecule acts like a spring and compresses 1.13% upon becoming charged. Determine the effective spring constant of the molecule.


equations that should be used are: F=kx and F=ke (Coulomb constant) q1q2 / r^2


you can find x, the distance the spring is compressed by multiplying 2.09x10^-6 x .0113 = 2.3617x10^-8 m

you can find the force by using coulomb's law; use have all the info to plug in except for the charges (q1 and q2). what are they? once you know the charges, you can solve for F and then plug into F=kx to solve for the spring constant. please help!

ccaramel Nov16-07 04:49 PM

nvm... i figured out the answer. the charges used are that of a proton and electron (1.6x10^-19)


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