What Is the Effective Spring Constant of a Charged DNA Molecule?

AI Thread Summary
The discussion focuses on calculating the effective spring constant of a charged DNA molecule, which is 2.09 µm long and compresses by 1.13% when ionized. The compression distance is determined to be approximately 2.3617x10^-8 m. To find the force acting on the molecule, Coulomb's law is applied, requiring the charges of a proton and electron, both valued at 1.6x10^-19 C. Once the force is calculated using these charges, the spring constant can be derived from the equation F=kx. The problem was ultimately resolved by the original poster, confirming the use of proton and electron charges.
ccaramel
Messages
2
Reaction score
0
A molecule of DNA (deoxyribonucleic acid) is 2.09 µm 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!
 
Physics news on Phys.org
nvm... i figured out the answer. the charges used are that of a proton and electron (1.6x10^-19)
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »
Thread 'Correct statement about a reservoir with outlet pipe'

Thread 'Correct statement about a reservoir with outlet pipe'

The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
View full post »

Similar threads

What is the effective spring constant of a charged DNA molecule?
Replies
1
Views
2K
Calculating the Effective Spring Constant of a Charged DNA Molecule
Replies
3
Views
2K
Find spring constant k using an electrical circuit
Replies
10
Views
2K
Multiple choice Q: Mangetic fields and Spring Constant
Replies
8
Views
2K
Problem with solving for force constant k of spring?
Replies
3
Views
2K
Determine the effective spring constant of the molecule
Replies
7
Views
7K
Trouble understanding the influence of a real spring in a system
Replies
3
Views
2K
How Do You Calculate the Spring Constant of a Charged DNA Molecule?
Replies
4
Views
14K
What is the Spring Constant of a DNA Molecule?
Replies
2
Views
5K
Amplitude of a mass joined to a spring in the presence of an E-field
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top