What is Tension: Definition and 1000 Discussions

Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows heavier than water i.e., denser than water objects such as razor blades, insects (e.g. water striders), to float and slide on a water surface without becoming even partly submerged.
At liquid–air interfaces, surface tension results from the greater attraction of liquid molecules to each other (due to cohesion) than to the molecules in the air (due to adhesion).There are two primary mechanisms in play. One is an inward force on the surface molecules causing the liquid to contract. Second is a tangential force parallel to the surface of the liquid. This tangential force (per unit length) is generally referred to as the surface tension. The net effect is the liquid behaves as if its surface were covered with a stretched elastic membrane. But this analogy must not be taken too far as the tension in an elastic membrane is dependent on the amount of deformation of the membrane while surface tension is an inherent property of the liquid–air or liquid–vapour interface.Because of the relatively high attraction of water molecules to each other through a web of hydrogen bonds, water has a higher surface tension (72.8 millinewtons (mN) per meter at 20 °C) than most other liquids. Surface tension is an important factor in the phenomenon of capillarity.
Surface tension has the dimension of force per unit length, or of energy per unit area. The two are equivalent, but when referring to energy per unit of area, it is common to use the term surface energy, which is a more general term in the sense that it applies also to solids.
In materials science, surface tension is used for either surface stress or surface energy.

View More On Wikipedia.org
  1. dcmf

    Find tension using sum of torque (two strings, one beam, one box)

    Here's the picture of the situation described, provided by the question. Here's a screenshot of the work I have done. Here's a screenshot of the submission screen. The issue is that I have one attempt left and am not sure what I am doing wrong. Based on the hints, I feel like I'm...
  2. daisy7777

    Uniform Circular Motion: Tension Force at Top of Circle

    I calculated the acceleration which is 0.804m/s^2. From there I calculated the centripetal force which is 0.402N. I think my lack of answer is due to my lack of understanding of the concept of what the centripetal force is at the top of the circle. Would it not be Fc = Fg - Ft as the ball...
  3. dcmf

    Tension & Circular Motion Question - Looking for speed

    I have attached a screenshot of my rough work. First of all, is my interpretation of the question correct? Please see the diagram in purple. To me, this makes sense because a=v^2/r is the only equation from my coursework that seems to relates radius (which you can find from the length of the...
  4. chwala

    Find the Tension in the cable when the lift is moving at constant speed

    aaaah just realized the solution after typing here... ... at constant speed, ##a=0##, therefore ##T-mg = 0## ##T=(1050 × 10) =10, 500## Newtons or any insight...welcome. Maybe i should ask...when the lift is moving downwards and there is deceleration then would the Tension be treated in...
  5. I_Try_Math

    Tension in a bungee cord

    (a) x = 16.7 Since x > 4.88, k = k_2 = 111 N/m. T = F(16.7) = k_2*x = 111*16.7 = 1853.7 N The answer key says the correct tension is 2320 N. Any help is appreciated, I'm not seeing where my math is wrong.
  6. I_Try_Math

    Find tension in string between two blocks on horizontal surface

    Did I draw the free body diagram incorrectly by treating the two blocks as one system? My textbook claims the answer is 25 N.
  7. S

    Tension Question with One Mass and Two Pulleys

    My question is how come the tension in pulley 2 is pointing downwards. I was under the impression that tension always points away from the mass.
  8. Quantum Psi Inverted

    A rope, a pole, and some tension

    A rope wraps an angle θ around a pole. You grab one end and pull with a tension T0. The other end is attached to a large object, say, a boat. If the coefficient of static friction between the rope and the pole is µ, what is the largest force the rope can exert on the boat, if the rope is not to...
  9. I

    Monkey accelerating up and down a rope

    Body M has a mass of 80kg and monkey has a mass of 20kg. No friction between table and the object M. Can someone please explain to me if the acceleration of the system will be greater with monkey accelerating up or down(relative to the rope), and why. Monkey accelerates both up and down at...
  10. Chrono G. Xay

    I Behavior of Clamped-Edge Circular Membrane

    I am working on a project that would help guide aspiring drummers and percussionists in determining what thickness of drumhead to select for the tuning they want and/or the “feel” they want. (More on just what “feel” is later). I’m trying to slowly work my way toward this starting with the...
  11. J

    Why are the forces on torque tension and not the weight of the mass?

    Let the left string be T1 and the right string be T2. Pretend that the masses are NOT equal and that the total mass on the left is 3mg and the total mass on the right is 2mg. My first thought: Net torque = 3mgR1-2mgR1 Actual solution: Net torque = (T1-T2)*R Once again, the force that's used...
  12. P

    Problem involving space elevators

    (a) The length ##h = L## for which the tension is minimum is the length that corresponds to the geostationary orbit, where the angular velocity of the cable matches the angular velocity of the Earth. This is because at this point, the centrifugal force balances the gravitational force, and the...
  13. H

    If tension provides the torque to this pulley, what is its equation?

    15 - Tension = 1.53*a T = 15 - 1.53*R*α T*0.33 - 1.10 = Iα Is this approach correct?
  14. Venturi365

    Relationship between horizontal force and friction in an exercise

    The thing with this exercise is that I don't think that the question makes sense at all (or, at least, is incomplete). First of all, we don't know if the mass moves with any of those tensions, therefore I cannot know which coefficient apply. Second of all, even if we suppose that the mass is...
  15. Tesla In Person

    2 pullies and 3 masses -Tension

    Hi, If i have a system that consists of 2 pullies and 3 masses, what is the tension on each part of the string? I know that for 2 masses hanging on either side of a pulley, the tension is the same. But for 3 masses, and 2 ideal pullies(no friction) and inextensible string, is tension the same...
  16. yashboi123

    Tension in cable D is equivalent to the tension in cable B?

    I found the tension of cable B by doing mg + Csin(37.1). I found C by doing 757(Tension in cable A) = Ccos(37.1). I was just wondering if the tension in cable D is equivalent to the tension in cable B. If possible please show the steps on how you determined if they are equivalent or not. Thank you!
  17. JohnnyLaws

    Finding the angle that a string makes with a wall and its tension

    For a better understanding of this exercise here is the image illustrating the scenario described in the statement: So to solve this exercise I began by drawing a forces diagram: I believe I have explained everything in the "Relevant equations" section. What am I doing wrong? The book that...
  18. Say17

    Calculating Tension in a System of Trolleys

    Hi all, To find out the tension. First I have to find out the a. 1. step F = ma F = (m1+m2) *a F = (1+3)*a F = 4*a F/4 = a F = 10N + 50 N F = 60 N 60/4 = 15 m/s^2 2.step T =( m1/ (m1 + m2)) * F T = (1/ 1+3) * 60 T = 15 N But the final result is 20N. Thanks for your help!
  19. S

    Misc. Knot(s) to tie end of fishing line under tension

    Hi. I need to tie some nylon monofilament fishing line so that it’s under tension. (Only moderate tension is needed – pulling by hand to make the line taut is sufficient.) I can tie one end to a support, e.g. using a using a ‘uni-knot’. Then the line will need to be stretched and the other end...
  20. A

    Tension in Rope Wrapped Around a Rod

    On question B, I've attempted a solution that I have posted. However, I don't think it's correct. Am I allowed to treat this rope that wraps around the rod as a "negative" force and simply attach it to the other side of the equation such that ## m_1g=m_2g+\mu_sN##?
  21. Mohmmad Maaitah

    Find tension in ropes connecting 3 masses being pulled on a surface

    This is the problem and my answer below it. my friends said it's 250 N and I say it's 100 N based on what I solved what am I missing ?? my try:
  22. Justforthisquestion1

    Pulling a yoyo over a surface with tension

    My Work so far: So there is a Force F applied to the right and since we have a no slipping condition we have a static friction force fs to the left. So the only thing that can move the center of mass (cm) of the yoyo is rotation. F would lead to a ccw rotation and fs to a clockwise rotation...
  23. P

    Tension in a spring that's bent into a semicircle

    Is this even solvable? I don't know where to begin.
  24. D

    Solving for Tension in Net Force Equation: Need Help!

    I have tried finding the tension of the string through the equation Net Force = T - mg = ma but I am struggling with coming up with the correct acceleration. Is my net force equation correct?
  25. C

    How does soap water membrane thickness affect surface tension?

    1.If the thickness of soap water surface decrease, whereas the concentration remain the same, how will the surface tension change? 2. If the membrane of soap water start to evaporate, its thickness become thinner and it’s concentration increase, How will the surface tension change? Thank you!
  26. chwala

    Find the tension in the two strings

    This is an exam question - refreshing as usual. Literature Overview; In the free-body diagram shown above, we can see the horizontal and vertical components of the tension forces, T₁, and T₂. Forces are vectors, which means they always have both magnitudes and directions. Like all vectors...
  27. V

    Surface Tension: Plate-Water Interface

    I would think that a force due to surface tension would act upwards on the plate and not downward, as shown in the diagram I have come up with. The surface of water would act as a stretched membrane and therefore there would be a surface tension on water surface in contact with the bottom of the...
  28. Spocktastic

    Trying to Figure out Tension force angle on Arm

    I already solved for part a, setting the sum of the Torques of the arms and deltoid equal to 0 and subbing in values which lead to a tension force of 870N in the deltoid. For part b, I remembered the law of static equilibrium, so the summation x and y components of all the forces in the system...
  29. M

    How do I solve a tension and torque problem without prior knowledge?

    I have no idea where to start or how to do this. I haven't learned this in lecture yet
  30. samy4408

    Trying to understand alveolar surface tension

    Hello, I learned recently about alveolar surface tension, and the explanation provided in the course was not satisfactory, it said that it is due to the force that pushes water molecules of the outer layer to the inner layers, I don't understand why this force that pushes water toward the cell...
  31. M

    A 4kg mass sits on a frictionless table....

    I got 13N but is that right because apparently, it's wrong Here's my work: F = mg = 2(10) = 20N F = ma a = F/m = 20/4+2 = 20/6 = 10/3 = 3.3m/s^2 T = mg - ma T = (2kg)(10m/s^2) - (2kg)(3.3m/s^2) = 13.4 N I appreciate it! And if I'm wrong could you show how you got your answer? Thanks
  32. babaliaris

    I Pendulum Tension Force -- How to calculate the full vector?

    Hello! I'm trying to understand how this pendulum works. I found this video that explains how to calculate the T force from the rope. He uses the preservation of kinetic and potential energy in order to find the magnitude of the velocity and then using Newton's second law, he calculates the T...
  33. P

    Why are tension and friction in the same direction?

    For the box I understand it’s just normal and force of gravity as well as tension pulling them, it was declared to have no friction so it just points up down and right. It’ll be accelerating right. The second person again has the normal force, gravity and the tension going to the left as a...
  34. gary808

    Mystery of a Tensioned Rope Split in Two Places

    I'm attempting to repair my Ergotron Workfit station. After taking apart, I discovered the problem. A single nylon rope split, releasing the spring's tension. Because it is past the warranty, the manufacturer is recommending I toss the whole assembly and buy a new $650 one. Doesn't seem the...
  35. R

    Solving the Rewinding Tension Control Puzzle: A Production Engineer's Story

    So, this problem is going to require some explaining.. I'm a Production Engineer who's recently started working at an adhesive tape converter/distributor and I've been working on an industrial rewinding machine for films, tapes, foams etc. The tapes I rewind range from 0.2mm - 3mm thickness...
  36. S

    Calculating Max Tension, Final Angle for Swinging on Rope Over Lake

    Please tell me if I need to post my solution for this.., but I just have a question more or less 'conceptual' question about (c). so I know that from Newton's 2nd law for centripetal acceleration --> ##F_{rope} - mgcos(\theta) = ma_n## where ##a_n = \frac {v^2}{R}## such that where the normal...
  37. pandatime

    Conceptual question involving tension and angles

    I have actually already partly solved a), as I do get the concept behind how to find tension through making sure that the net force in the x and y direction are zero. Here are my answers for a) T1 = T5 = 2mg/sin(theta) T2 = T4 = mg/sin(phi) T3 = mg*cot(phi) The reason I am asking this...
  38. mcconnellmelany

    Investigating Lagrangians and Constraints for Tension Calculation

    I had used the same constraint as the solution manual says. So my two Lagrangian would be ##L_1=\frac{1}{2}m_A\dot{x_A}^2+\frac{1}{2}m_B\dot{x_B}^2+\frac{1}{2}m_C\dot{x_C}^2+m_Cgx_C+T(x_A+x_B+2x_C-c)## whereas c is just a constant. Of course, I have to write my Lagrangian using constraints...
  39. Rikudo

    Tension in a complex-pulley-system

    In equilibrium position, the pulley that holds mass C (we will call this pulley C later on) is pulled upwards by spring S . Hence, the string around the pulley C becomes tense. Now, if spring S is cut, my intuition says that the tension around this pulley will become zero, and mass C will...
  40. mcconnellmelany

    Is it possible to find Tensional force from Lagrange?

    Lagrangian principle is easier to solve any kind of problem. But we always "forget" (not really. But we don't take it into account directly.) of Tension in a system when looking at Lagrangian. But some questions say to find Tension. Since we can get the equation of motion from Newton's 2nd law...
  41. A

    I Block with upward velocity tethered to a bottom block

    If I shoot a block with mass m1 with initial velocity v, and the block m1 goes to the end of the string tethered to the bottom block with m2 without lifting it up, what is the force equation involved with the block with m1? I am torn between whether it would be 1) -T -m1*g = 0, which I am...
  42. V

    Finding tension as a function of distance from the center of rotation

    I'm not too sure how to account for both the mass and the rope at once. I think the following are true for the two individually: For the mass at the end, ## T = m ω^2 L ##, following from ##a = v^2/r##and ##v=ωr##. For the rope, ##dT = ω^2 r dM##, where ##dM = λ dr## and λ is the mass per unit...
  43. Rikudo

    Tension between two rigid bodies

    Ok. So, I already worked on this problem, and get ##m_c## = 2m/3, which is correct according to the book. However, I also want to know the value of the tension (T) between rod A and B. Note: Before we start working on my modified question, I want to point out that the force exerted by the...
  44. A

    I My textbook is deriving wave speed on a string under tension

    My textbook is deriving wave speed on a string under tension with confusing thetas. It assumes ##\tan \theta_1 = \frac{-F_1}{F_T}## and ##\tan \theta_2 = \frac{F_2}{F_T}## which confuses me. I know for sure theta is the angle due to the position of y and x, ##\tan \theta = \frac{y}{x}##, but I...
  45. L

    I Surface tension and water (the smallest hole water will flow through)

    I am trying to find out what the smallest hole water will flow through. not a molecule of water, just water in general. Here is an example. I have a single walled cube that i 3d printed. When i put water in it, it leaks between the layer lines. I want to find out what the spacing between the...
  46. A

    Tension in string pulling two carts

    F - T = m*a 820t - T = m*0.7805t T = 820t - m*0.7805t I am confused what I would use as mass? Mass of cart A, or mass of cart A and tractor?
  47. kingofjong

    I Maximizing Compound Bow Power: The Role of Longer Limbs Explained

    Hello If a compound bow has longer limbs will it have more power? Longer limbs means more limbs, hence more tension is building when limbs bend. That tension transfers to the bow string. Is this a true statement. I know there are other factors for making a powerful compound bow. Is long limbs...
Back
Top