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.
Homework Statement
you want to hang a 15-N picture as in part (a) using some very fine twine that will break with more than 12 N of tension can you do this? what if you have it as illustrated in part (b) of the figure?
Homework Equations
Σf=ma
The Attempt at a Solution
[/B]
okay i started...
Homework Statement
In the figure above a block of mass m is connected to a block of mass M > m by a string. Both blocks sit on a smooth surface with a coefficient of kinetic friction µk between either block and the surface. In figure a), a force of magnitude F (large enough to cause both blocks...
1. Derive an equation for the acceleration of both the cart and suspended mass in
terms of both masses (Mc and Ms ), the angle of the incline (θ), and the acceleration due to gravity (g).
Homework Equations
Fx=
T - Mgsin θ = Ma
T = Mgsin θ + Ma
Fy
T = mg - ma
Combine the expressions...
Homework Statement
This is not HW problem specific, but more of a lack of understanding for an equation in answer.
A pair of students are lifting a heavy trunk on move-in day. (Figure 1) Using two ropes tied to a small ring at the center of the top of the trunk, they pull the trunk straight up...
Homework Statement
What's the difference between Oxygen Tension And Partial Pressure
Homework Equations
...uh...rules of grammar ?
The Attempt at a Solution
If I knew the solution I wouldn't be here now would I ?
Here are a few links
https://en.m.wikipedia.org/wiki/Blood_gas_tension...
This is a bit of a general question.
Say that there's a block on a ramp, with a (massless) rope attaching it to the top of a ramp. If we're given values for the mass of the block, maximum tension, and coefficients of static and kinetic friction, how would we determine the friction or tension...
1. A small drop of fat floats on the surface of a liquid whose surface tension is s. Surface fat tension at the air-fat interface is s1, at the fat-liquid interface is s2. Determine the thickness of the drop if its radius is r.2. ##F=\sigma l##
##\delta P=\sigma (\frac 1 R_1 + \frac 1...
1. The films of the two liquids are separated by a bar of length l. The coefficients of surface tension of liquids are equal to s1 and s2, respectively. What force acts on the bar on the liquid side?(It is a rectangular surface of 2 liquids separated by a bar of length l)
2. Force=(surface...
1.The lotus effect refers to self-cleaning properties that are a result of ultrahydrophobicity as exhibited by the leaves of "lotus flower". Dirt particles are picked up by water droplets due to the micro- and nanoscopic architecture on the surface, which minimizes the droplet's adhesion to that...
Homework Statement
The pendulum cord is released from rest when the angle = 0 (from a horizontal)
If the string breaks when the tension is twice the weight of the bob at what angle does it break?
Im from NZ and our NCEA system is often riddled with mistakes and I want to clear this up.
Is the...
Homework Statement
Homework Equations
$$
J \space (\text{Impulse})= \Delta (mv) = F \times \Delta (t)
$$
The Attempt at a Solution
As much I interpreted, we have to calculate the impulse caused by the tension till the relative velocity of approach along the string becomes 0. T to this, I...
Homework Statement
Homework Equations
Work Done=Force*Displacement in the direction of the force
The Attempt at a Solution
I tried to solve the problem this way,
I wrote these equations for the two masses,
T-mg=ma...(i)
Mg-T=Ma...(ii)
From (i)&(ii), T=[M(g-a)+m(a+g)]/2
and then I would...
Let's say that we have two blocks - 2 kg and 1 kg.
They are connected with a rope that can stand the maximal tension of 20 N.
Does the maximal force we can apply to the block so that the rope does not break apart depend on the choice of the block?
Let's say that we have two guys, each weighs 50 kg. They are pulling a piece of against each other as hard as they can. The tension of the rope will therefore be the force of friction acting on each of them (the same magnitude).
Now, let's say that a third person joins the party and grabs the...
Homework Statement
Problem: 4.93[/B]
The pulley is assumed massless and frictionless. The mass of the object attached to the pulley is given in terms of m, the force applied to the pulley is F (refer to diagram), and frictional force is f.
Question: Find the acceleration of the mass m in...
Homework Statement
I am trying to find the forces in KJ, CJ, and CD.
Homework Equations
ΣFx=0
The Attempt at a Solution
I found the magnitude of KJ to be 26.8kN, which is correct (according to answers in the back of the book). I believe it is a compressive force. The book lists all 3 forces...
When my professor sums external forces (to know if the impulse is constant or not) he always includes tension.
I will use as an example pic related. If my system includes the two particles and the thread, woudn't tension being a internal force?
I'm sorry if it's a silly question, but I also...
Homework Statement
In the figures:[/B]
Are T and T2 same?
Homework Equations
This is just a yes and no answer[/B]The Attempt at a Solution
I don't want anything solved. I've actually solved it already and have gotten T2= T
NOTE( T≠T1 here)
Homework Statement
We have to find T1 and T2
From right to left objects are: A B C
Homework Equations
F=ma
The Attempt at a Solution
Okay. So I found acceleration of whole system:
F=ma
200N= (20+10+5)*a
200/35=a
a= 40/7 ms-2
Now, finding T1 is fairly simple:
f=ma
T1=5*(40/7)
T1=200/7 Newtons...
I am trying to compare an experiment on spinal changes due to zero-g in astronauts. Researchers simulated zero-g spinal elongation by suspending human subjects so that no part of their body touched the ground.
This figure shows the % change in disc thickness for each subject compared to data...
Homework Statement
The surface of a liquid is just able to support the weight of a six-legged insect. The leg ends can be assumed to be spheres each of radius 3.2 × 10−5 m and the weight of the insect is distributed equally over the six legs. The coefficient of surface tension in this case is...
Homework Statement
I have a rope held by a hook, which is attached to the ceiling by a chain (with an angle theta), in one side, the rope (with an angle alpha) is attached to a a wall, in the other side, the rope is carrying an anvil of 110 Kg mass in vertical position. What is the tension in...
Homework Statement
mass of pulley is 8 kg
Homework Equations
m1a=T
m2g-T=m2a
The Attempt at a Solution
I solved question with neglecting mass of pulley but should I?
Homework Statement
Is the tension in the string of a pendulum, when averaged over time, larger or smaller than the weight of the pendulum? Quantify your answer. You may also assume that the angular amplitude of the oscillations is small.
Homework Equations
For tension ##T##, angular...
Homework Statement
Homework Equations
g is the acceleration due to gravity
a is the acceleration of system
The Attempt at a Solution
g is the acceleration due to gravity
Force=3(g+a)
Force=6(g-a)
solving both equations,
a=g/3
tension =force=4g
How do i calculate tension in the particular...
I attempted the question but it was wrong... I don't understand where i went wrong my working seems logical, can someone please help.
When a needle is gently placed on the surface of still water (γ = 0.0730 N.m-1) it can be supported by surface tension if the mass of the needle is small enough...
Homework Statement
Homework Equations
m:mass of solid cylinder
T: tension in string
w:angular velocity
The Attempt at a Solution
m(g-a)=T
mg-ma=T
a=v^2/r=w^2r
now what?
A steel washer is suspended inside an empty crate from a light string attached to the top of the crate. The crate slides down a long ramp that is inclined at an angle of 37 above the horizontal. The crate has mass 154 kg. You are sitting inside the crate; your mass is 61 kg. As the crate is...
I derived a relationship between frequency and tension of a string, accounting for tension's effect in the linear density of the string.
So in a nutshell, the equation is more complicated and is in the form of
f^2=aT^2+bT (f is frequency, T is tension, ab are constants involving the control...
1. The problem statement, all variables, and given/known data
So I'm doing an IB extended essay on the relationship between frequency and tension of a violin string. As you apply more tension to the string (using weights and pulley), the frequency will be higher, as shown below. There's not too...
Homework Statement
A 110 kg panda is riding on a 3.0 m long swing whose mass can be considered negligible. The highest point of its arc occurs when the swing makes a 20° angle with the vertical. What the magnitude of the total tension in the ropes of the swing at that point?
m (mass of panda)...
Homework Statement
There is a metal stick that is connected to the ceiling with another one. The angle between them is 60°. Calculate the tension force of the bottom one.
Homework Equations
T = f N
or actually none, except trygonometry
The Attempt at a Solution
[/B]
I tried using this...
Hi all!
I am doing an experiment where we create a standing wave by attaching a string to a hanging mass at one end and to a string vibrator at the other (the string passes through a pulley). When plotting the graph, the slope is inevitably 1/(u*f^2) where u is the linear density and f the...
Homework Statement
Two blocks each having masses of 3.3 kg are connected by a wire CD and the system is suspended from the ceiling by another wire AB.The linear mass density of the wire AB is 10X10^-3kgm^-1 and that of CD is 8X10^-3.The speeds of the transverse waves produced in AB and CD are...
Homework Statement
What is the tension of this rope?
Cosmonaut m=100kg is outside of spaceship M=5 tons on rope with length 64m. Cosmonaut along with his spaceship moves in orbit at a neglible distance.
m=100kg
M=5000kg
L=64m
Planet's mass 6*10^24
Planet's radius 6400km
Homework Equations...
Homework Statement
Two pith balls each have a mass of 1.0g and equal charges. One pith ball is hung from an insulating thread. The other is fixed at a horizontal distance of 3.0cm from the first, The first hangs at an angle of 30.0° from the vertical. Find:
a) the gravitational force on the...
1. Homework Statement
The magnitude of the force F is slowly increased. The direction of the force remains the same. What is the magnitude of the force F at the moment the block looses contact with the floor?
Homework Equations
fnet=m*a[/B]The Attempt at a Solution
fnety =...
Homework Statement
A force F is applied horizontally to a block A of mass mA =
0.600 kg so that it slides on the floor with acceleration g/3.
Block B of mass mB = 0.200 kg rests on top of A, but is kept
in place by a cord which is tied to the wall at 45.0°. The
coefficient of kinetic friction...
Hi,
I am interested to find out the answer to whether high tension or low tension strings on badminton/squash rackets give more power/force. There are so many conflicting sources on the internet I wanted to see if it can be answered in a concrete way by physics. So, some sources are saying that...
Homework Statement
We have two very long wires, each with the same mass of 20 grams per meter. They are hung from the ceiling with two identical wires. When they both had the same current flowing to the opposite directions, they created the same angle.
We double the current in one of them, is...
Homework Statement
You spin a 1.20 kg mass at the end of a 1.10 m string. The tangential velocity is 13 m/s. What is the tension in the string?
Homework Equations
x = angle string makes to the vertical
L = string length
r = L*sin(x)
T*cos(x) = mg (because the sum of the vertical forces has...
I know how to solve this problem with x and y components but how do I solve it with the equilibrant/resultant method? I don't understand how you can make a triangle with both F1 and F2 when in the diagram it looks like the magnitude F1 is only partially represented? Why are we just ignoring the...
Homework Statement
[/B]Homework Equations
[/B]The Attempt at a Solution
In the second question at 5:32,why doesn't the block have a spring force.In FBD of 2nd block it should have been mg-(T+kx)=ma right?
Homework Statement
Block B is positioned on a fixed incline. Attached to block B is a massless, ideal string that runs over a massless ideal pulley and is attached to a hanging block block A at the other end. The mass of block A is 2 kg and the mass of block B is 10 kg. The angle of the incline...
Homework Statement
A meter stick with a mass of 260 g is supported horizontally by two vertical strings, one at the 0-cm mark and the other at the 90-cm mark
A) What is the tension in the string at 0 cm
B) What is the tension in the string at 90 cm
C) The string at the 90-cm mark is cut. What...
Homework Statement
The tension in the skin of the left ventricle of heart is 4.90 N/m. A cut is made on the left ventricle during surgery. How many stitches must be used to repair the cut? Each stitch will safely support a tension of 0.4 N.
Homework Equations
Surface tension = force/length...
Hi everyone. I found this image online that made me question a couple of things that might be a bit humiliating to ask:
I always thought that tension is simply a pulling force, meaning that the mass is suspended because the tension force pulling the mass is equal to the weight force of the...
Question One
What would be the effect on the following if the load torque is increased and the speed maintains constant (give reasons for your answer):
A. the tension in the tight side of the belt
B. the tension in the slack side of the belt
C. the power transmitted.
Not sure on how to solve...
Hi .how can i calculate the molar volume and surface tension of nanoparticles ? shoud i have to calculate? or these parameters is available in tables or sth?