# What is Push: Definition and 204 Discussions

Push technology, or server push, is a style of Internet-based communication where the request for a given transaction is initiated by the publisher or central server. It is contrasted with pull/get, where the request for the transmission of information is initiated by the receiver or client.
Push services are often based on information preferences expressed in advance. This is called a publish/subscribe model. A client "subscribes" to various information "channels" provided by a server; whenever new content is available on one of those channels, the server pushes that information out to the client.
Push is sometimes emulated with a polling technique, particularly under circumstances where a real push is not possible, such as sites with security policies that require rejection of incoming HTTP/S requests.

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1. ### The ideal weight or force to push a drill

What is and how is the estimation of the ideal weight or force to push (bit being in) a driller down when drilling (stainless) steel to bore 3-9 mm hole?
2. ### How much air pressure is needed to push water up a column?

Hello, I was creating a device to move water up a tube using air pressure, but I am not certain how much pressure I would need. I attempted to create it using 5 gallon buckets, however I was unable to apply the needed pressure needed to the airtight container. The image below is what I have...
3. ### I need a small fan to push a lot of air because my bigger fan is too loud

I remember a quick demonstration in high school of air like pushing more air thru a tube maybe 3-4in dia. than the little airbrush would push by itself? I think. I scaled that up at a weld shop with shop air and a 10in alum pipe that was like 3 feet long. I put a blow gun in the pipe and made a...
4. ### MHB Forward Unit Push Operator Equation

Hopefully the symbols I am using are standard. I will define them upon request. I have a theorem that says, given a difference equation \left ( \sum_{j = 0}^m a_j E^j \right ) y_n = \alpha ^n F(n), we can define a polynomial function \phi (E) = \sum_{j = 0}^m a_j E^j such that \phi (E) y_n =...
5. ### B Speed of Push vs Speed of Light

Been thinking about this since I was 12. Suppose you had a 1 lightyear long pole, and on the other end was a button 1 inch away that activates a light. The light is powerful enough for you to see it 1 lightyear away. You push the pole 1 inch forward. How long does it take for the light to reach...
6. ### Calculating Force to Push Steel Rod Up 50 cm

Hello ,all I'm calculating the force that required to push steel rod up 50 cm into water filled steel tank . pls see picture . If i exclude negligible friction force (which is friction between steel rod and water sealing gaskets ) Total Force = Force to lift 40 kg rod + Fluid Force...
7. ### I What Lens to Put In Front of an Complex Lens to Push Focal Plane Back?

I have an extremely fast (f/1.05) night vision optic that I scavenged from a old night vision unit which is faster than current production lenses (f/1.23). However due to the design of newer night vision tubes, the lens will not focus to infinity on the night vision tube. This is because the old...
8. ### B What happens when you push a rod?

Note, I put this question here because I imagined it fit the best here, but mods feel free to move it if there's a better place. So my girlfriend asked me a question today I couldn't answer. Imagine you have a crystal rod (for simplicity), and you push it a bit at one end, in the axial...
9. ### Calculating Where to Push to Straighten a Rod

I have some threaded rods on my 3D printer that I want to straighten. After searching Youtube for a quick easy method that doesn't involve a million "guess and check" steps, I found this: This guy seems to have concocted some method using Fourier series to straighten his rods. Not sure...
10. ### B Push from a Narrow Base vs Wide Base

Hello! When moving an object, how do you describe the changes when you push from a narrow base vs a wide base? For example, say you push something heavy with your palm vs your index finger. It feels easier to push from a palm rather than a finger even if the force from my arm is the same but...
11. ### Asking for help with a physical problem that uses a piston to push water

Consult a physical problem that USES piston to absorb water: Pistons with surface areas S1, S2 and S are placed horizontally at the same height (H). S1 = S2 S=S1+S2 When F starts moving to the left, how do you calculate its force? Is F=ρgHS? (*The friction force doesn't have to be calculated.)
12. ### B What does a rocket push against?

I feel ok that in our atmosphere there is pressure that is a force to push against. But in a "vacuum" there is very little element available to push off of. I had some experience with near space high vacuum here on earth. The machinery was able to get down to analysis of element composition of...
13. ### Force Needed to Push Bodies in Space: 100kg vs 1kg Mass

Do we need more force to push a body with 100kg mass than of 1kg mass in space(in vacuum)?
14. ### I How to Calculate the force to push a wheelchair up a ramp?

How do I calculate the required push force (in kgf) for pushing a wheelchair up a ramp? - the ramp has a 5 degree incline - the weight of the chair and person in it totals 96.8 kg - the wheelchair has 4 wheels, all of equal diameter (15 cm) - the wheels on the wheelchair have a rolling...
15. ### Auto/Motor How Can I Make My DIY Swirl Push Maker Create Perfect Spirals?

Hi Everyone! I am trying to a DIY project to make a food maker. I am 50% succeeded with that and need help for the remaining 50%. The idea is to produce the output shown in the first image. That food is made with a flour. So I have the setup a pressing machine shown in image2. In this I was...
16. ### B ΜStatic = μDynamic: Easier to push a moving object?

I was running into some weird behavior in a game (Unity/PhysX), and it got me to wondering whether the behavior was reasonably accurate, or whether it was a bug in the physics simulation. The issue related to friction, in a potentially unrealistic case where Static and Dynamic friction are...
17. ### Push Mercury out to Venus' orbit?

So it would be cooler and mine-able? Given unlimited tech and wealth in a fictional setting.
18. ### Calculating a push force using area, speed, and density?

Homework Statement The doorway in the previous question measures 1.06 m x 2.04 m, and the wind blows parallel to the wall surface at 3.89 m.s-1. Calculate the force pushing the curtains out of the doorway. The density of air is 1.29 kg.m-3. Known data: A = (1.06m)(2.04m) = 2.162 m^2 v(wind)...
19. ### Programs Returning to Physics After 4 Years: Should I Refresh or Push On?

Perhaps this isn’t the place to ask, but I was just looking to hear opinions from some people on here about my situation. I’ve been out of school for 4 years now, having left to enlist with the Air Force. While in school I was majoring in Physics/Mathematics. I was a B student in Physics 1, 2...
20. ### Force needed to push a trolley onto sidewalk

Homework Statement Find minimum Force needed to push the trolley onto the curb. Homework Equations Torque=r x F The Attempt at a Solution The front wheel will rotate about point b if the trolley is pushed onto the sidewalk. This should mean that as soon as the wheel has a positive torque...
21. ### Find the force to push a book sideways on a table

Homework Statement Place a book flat on a table and press down on it with your hand. Now suppose the hand-book and table- book values of are 0.50 and 0.40, respectively; the book's mass is 0.90 kg and your downward push on it is 10 N. How much horizontal force is needed to keep the book moving...
22. T

### B Why when you run then kick a wall you feel an upwards push?

Sounds wird but I tried it and people use this it help clime walls. How does this happen?
23. Y

### Automotive Construction of CVT Metal push belt

I am trying to understand the construction of CVT Metal belts that are made up of steel elements and some rings. I do not understand the full construction details of the belt. The most detailed information I have got ever is in this PDF on page 5...
24. ### I Force Needed to Push a Manual Treadmill

I apologize if this is in the wrong thread, I'm new. I need to figure out how hard it would be for Jim to move the treadmill treads along its track of bearings. This isn't for homework, it's just something I want to know. Jim weighs 160 lbs. The rope isn't holding him up, it's there for him to...
25. T

### B Why it's easier to push the door from the furthest distance

Why it's easier to push the door from the furthest distance From the pivot point?
26. J

### Maximum height a waitress can push on a glass without it tipping

Homework Statement I have attached the problem. I will write it out: A waitress attempts to push a glass of water of heigh 15.o cm and diameter of 7.00 cm on a dining table, as shown in the figure. If the coefficient of static friction between the glass and the table's surface is 0.350, what...
27. X

### Optimal Technique for Opening Windows on a Moving Bus: Push or Pull?

So if in an ordinary bus, is it easier to open a window by pushing it upward while seated or by pulling it upward while standing? Question came up in our exams today. I answered while seated. Not quite sure though.
28. ### Confusion about work performed by a horizontal push or pull

Hello, Over the past couple of weeks I have been working my way through the basics of physics on my own. I've just arrived at work and energy and there is one thing that confuses me a little bit. Let's say I have a 25kg box on a sidewalk. I go to push it and I ultimately push it 5m east (lets...
29. ### How does a battery push charges? Potential difference?

Hello there, I'm confused on several things such as the potential difference it provides and how it pushes the charges through the wire or conductor or circuit. So when a battery comes into contact with a wire, the positive charges flows from high potential through the circuit to the low...
30. ### Can a magnet have more push force than it weighs?

Simple question. Can a magnet have more push force than the magnet itself weighs. Example: A magnet weighing 2kg having a push force equal to 3kg.
31. ### I Need a little push on this integral using trig substitution.

∫x2√(3+2x-x2) dx Here's what I've already done: completed the square ∫x2√(4-(x-1)2) dx (x-1) = 2sinθ sinθ = (x-1)/2 x = 2sinθ+1 dx = 2cosθ dθ trig sub + pulled out constants 4∫(2sinθ+1)2√(1-sin2θ)cosθ dθ trig identity 4∫(2sinθ+1)2√(cos2θ)cosθ dθ 4∫(2sinθ+1)2(cos2θ)dθ expanded + trig...
32. ### Voltage & Current & Push & Force & Potential

Homework Statement I’m trying to understand what voltage is. Getting confused. I've written my confusion as questions below and answered the questions. (i) What is voltage? (ii) What is voltage passing through a lightbulb? (iii) Is POTENTIAL just another...
33. ### How long does it take to push this block at an angle?

Homework Statement A 100 kg block is pushed across a level frictionless surface at a 60 degree angle, with a force of 20 Newtons. How many seconds does it take to go 100 meters? m = 100kg Mu = 0Homework Equations F = MA The Attempt at a Solution I sketched out the problem on my paper here...
34. ### IPhone 7 and AM push button radios....how did we get here?

Hi Guys, My old cell phone died so I got two new iPhone 7s, one for my wife and one for me. They were not free...lol Instead of talking to people, I now talk to my phone. I talk and it converts my redneck voice to text...lol No one actually answers their phone anymore anyway, so "leave a...
35. ### Calculating force needed to push sled down incline

Homework Statement Calculate the force required to push a 22kg sled down a 6 degree hill and have an ending speed of 60km/hr after traveling 75m when the coefficient of friction is 0.20. Homework Equations Fnet= ma (V2)^2 = (V1)^2 + 2a(d2-d1) Ff= uN W= mg The Attempt at a Solution I'll use @...
36. ### Need a little push. [Simple Physics Problems]

Homework Statement Question A car starts from rest and uniformly increases its speed at a rate of 0.7 m/s2 on a circular track of radius R = 253 m. What is the magnitude of the car’s net acceleration after 50 s? acen=.7m/s^2 t=50s R=253m Homework Equations Equations acen=(v^2)/r Maybe...
37. ### B If in a lift we can tell if acceleration is due to g or to a push

does that affect the equivalence principle?
38. ### Projecting push forward of a vector

Homework Statement Say we have two manifolds N(dim d) and M(dim d-1). Let Φ: M →N be a diffeomorphism where Σ = Φ[M] is hypersurface in N. Let n be unit normal field (say timelike) on Σ and ⊥ projector (in N) defined by: ⊥^a_b = \delta^a_b + n^a n_b Where acting on (s, 0) tensor projection...
39. ### Receiving all push notifications on smartwatch

I have a smartwatch that has bluetooth notifications enabled. According to that it should receive any push notification from mobile. I have an app installed called BT Notifications that sends some but not all notifications that I can see on mobile to smartwatch. I searched google but got...
40. ### Would You Push The Button? A Conundrum Discussion

Here's the idea of this thread. I start by posting a conundrum. It is basically this: if you push the button, something good will happen but at a price. The next poster then says whether he pushes the button or not and posts his own dilemma of the same kind. So let me start with the classic...
41. ### Momentum and push starting vehicles

Homework Statement This was a question I came across in my A level physics course: A garage attendant was surprised to be asked to give a lorry a push as the battery was flat. He was even more surprised when he leant on the back of the lorry and the slight movement of the lorry was enough to...
42. ### How does a vacuum pump push gas out of a container?

Precisely how does a vacuum pump take the gas, let's just assume air, out of a container?
43. ### How is a Push Solenoid Constructed Differently from a Pull Solenoid?

I was reading http://www.rossdecco.com/pdf/how_a_dc_solenoid_works.pdf about push and pull solenoids. I don't quite understand what differentiates the two in terms of construction. What I have is a copper wire wound around a tube and the ends are attached to a battery, like in this I believe in...
44. ### Could a Pulling Airplane Propeller Be More Effective Than a Pushing One?

Hi, I'll start by saying I'm new here. I'm in my first year at college and I want to be an inventor. My question is this - if there was an airplane propeller that could pull on air instead of pushing against it to create thrust, would it be more effective at 1. creating thrust and 2. avoiding...
45. ### If there is no acceleration, does that mean no force?

So last year, I was told by a friend that no Acceleration means no Force, Mathematically, this makes sense (500 Kg * 0 m/s^2 = 0 N), but intuitively, I can't wrap my head around it. Maybe this is because of language and the way we use the word force in normal conversation, but in physics it is...
46. ### How to create force of 3000 joules to push iron ball of 100gm?

Respected all my bros,, I want to creat force of 3000 joul to push the iron ball of 100 gm? The ball should go straight upto 10 meters at speed of 700 miles per sec.
47. ### Box Pushed Up an Incline Ramp: Basic Newton's Law Questions

Homework Statement A 90 kg box is pushed by a horizontal force F at constant speed up a ramp inclined at 28°, as shown. Determine the magnitude of the applied force. when the ramp is frictionless. when the coefficient of kinetic friction is 0.18 Homework Equations F=mg FN=mg μ= Fk/FN The...
48. ### Why did Newton think the apple was pulled, not pushed?

i was wondering, instead of thinking the apple was pulled down by some force to Earth , why didn't he think that there was a force pushed the apple down from above? , imagine when you leave in that particular year when he was alive.
49. ### Earth vs Space: Is a Falling Ball PULL or PUSH?

When a ball falls towards Earth, what is actually happenning... Is the Earth PULLING the ball? or Is the space PUSHING the ball? (Be assured that I can understand you. Before becoming a teacher of literature, I studied Physics, Chemistry and Mathematics upto graduation level. The previous...
50. ### Why Do Engineers Use Pullbacks and Pushforwards in Mathematics?

Hello I am a mechanical engineer who is teaching himself the math of exterior algebra and differential forms. It is not easy for me and I have had many SIMPLE stumbling blocks due to my not respecting algebra. May I ask for help on some simple aspects? (Please be patient with me.) My...