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.
I really cant wrap my head around how I can find the tension i in the rope going from A to D via the smooth pulley B.
P=4.91N
Distances are in mm
I assume I cant use the triangle EBD as it can be dynamic without the triangle ABC changing. I know I can find the y component of the tension in...
I'm struggling to get to the correct answer, which I posted down bellow.
The pulleys are ideal, so I figured that m₁ and m₂ will both move upwards (towards the ceiling?) with the acceleration a, while m₃ will move downwards with the acceleration -a.
Let T be the tension in the string which...
We know that net work done is equal to the change in kinetic energy, so we write: $$\Delta K = W$$ The tension is acting at angle ##\theta## due to the x axis, so we will only be taking its x component ##T_x = T \cos{\theta}##. Since we can look at this as one dimensional motion (##T_y## does no...
TL;DR Summary: Ping-pong ball hanging static from infinite plane of charge and a string
Really struggling with this question. I'm not sure if I have set up the free body diagram correctly and don't know how to set up the x and y components
In classical mechanics, the potential energy stored in an elastic stretched string is the work done by the tension during the stretching process. Is this concept and formula the same in Special Relativity?
Thanks in advance.
Hi everyone .
I need help on the following problem.
I built a current sensor that is based on the same principle as the Rogowski coil. Don't propose other alternative methods to measure the current because its application will be different and I don't want to talk about this.
in reality what I...
The first question statement was under the chapter ##Newton's Laws Of Motion (Without Friction)##. Whereas, the second question was under ##Friction##.
The free body diagram for the first question is given as:
And the free body diagram for the other question is given as:
In the first...
For point one I analyzed all of the forces, called the tension on the right ##T_2## and the left one ##T_1##, and taking as positive the clock-wise and upwards directions I found:
$$\begin{cases}
T_2 - mg = ma \\
N_2= T_2 + M_2g + T_1 \\
N_1= M_1g - T_1 \\
τ_{T_2} - τ_{T_1} = I_2 α_2\\
τ_{T1} =...
A cylindrical bag is made from a freely deformable fabric, impermeable for air, which has surface mass density σ; its perimeter L is much less than its length ##l##. If this bag is filled with air, it resembles a sausage. The bag is laid on a horizontal smooth floor (coefficient of friction µ =...
A few years back there was an issue called the Hubble tension where the observations were nor matching up to predictions when looking at the Early and late time data.
I had heard that one possible explanation is due to our being in an underdense region but have also read a counter paper to...
I understand that in the initial condition both the net torque and net force are zero since the system is in a static state , the net torque remains zero as the mass down is being pulled , the two blocks get pulled towards the axis of rotation by a radial force
but I am wondering what is...
for 4kg box:
Fx = T
m1a=T
(4) (2.50) = T
10 = T
for 6 kg box: Fx = Fa - T
m2a = m2a - T
15 = 15 - T
15-15 = T
0 = T
I assumed the tension would be the same for both boxes, they are supposed to be, so what did I do wrong and is the answer 10 or zero?
My interest is on part (a), the steps are clear. I thought the final solution ought to be
##T- 500 =50 ×0.2##
##T=500+10 = 510N##
Unless I am missing something here, same query on part (b).
Pretty much what the title says. Everything that I can find online addresses the pendulum problem with the assumption that the rope is under tension to start. What if the rope is slack to start? Will there be an increase in force applied to the pivot point, say if a mass is dropped off a...
I'm the technical director for a theatre group and am looking at the best way to get an actor to use a rope to swing on stage. As we rent the theatre we use I need to run everything by their staff, who doesn't have a solid grasp of mechanics and physics. I proposed that we lower a pipe from...
I have been taught that speed of pulse is v = √(T/μ), but here tension varies at each point therefore I cannot just simply apply the formula. I think integration would be needed, I tried but ended up nowhere. Can someone help me find the time?
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...
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...
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...
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...
(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.
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...
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...
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...
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...
(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...
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...
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...
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!
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...
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!
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...
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##?
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...
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?
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!
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...
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...
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...
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...
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
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...