What is Position: Definition and 1000 Discussions

The missionary position or man-on-top position is a sex position in which, generally, a woman lies on her back and a man lies on top of her while they face each other and engage in vaginal intercourse. The position may also be used for other sexual activity, such as anal sex. It is commonly associated with heterosexual sexual activity, but is also used by same-sex couples.The missionary position is the most common sex position, but is not regarded as the most favoured one. It may involve sexual penetration or non-penetrative sex (for example, intercrural sex), and its penile-vaginal aspect is an example of ventro-ventral (front-to-front) reproductive activity. Variations of the position allow varying degrees of clitoral stimulation, depth of penetration, participation on the part of the woman, and the likelihood and speed of orgasm.
The missionary position is often preferred by couples who enjoy the romantic aspects of ample skin-to-skin contact and opportunities to look into each other's eyes and kiss and caress each other. The position is also believed to be a good position for reproduction. During sexual activity, the missionary position allows the man to control the rhythm and depth of pelvic thrusting. It is also possible for the woman to thrust against him by moving her hips or pushing her feet against the bed, or squeeze him closer with her arms or legs. The position is less suitable for late stages of pregnancy, or when it is desired for the woman to have greater control over rhythm and depth of penetration.

View More On Wikipedia.org
Recent contents Top users
  1. A

    Obtaining Acceleration from Position vs Time graph

    I have collected data on a car accelerating down a straight track. I graphed it Position vs Time. Then I found the tangent slope at 5 points along the curve and plotted them as velocity. But then I linearized the position vs Time graph (position vs Time^2.) However, the slope of the velocity vs...
  2. F

    Acceleration as a function of position

    Hello Forum, If a force is a function of position x only, like Hooks's spring force F=-kx, the acceleration is also only dependent on the position x, i.e. a(x). At every instant of time t, the object has a specific velocity v(t), position x(t) and acceleration a(t), which all depend on the time...
  3. Z

    I Why the velocity operator commutes with position (Dirac equation)

    ##\hat{v}_i=c\hat{\alpha}_i## commute with ##\hat{x}_i##, ##E^2={p_1}^2c^2+{p_2}^2c^2+{p_3}^2c^2+m^2c^4## But in classical picture,the poisson braket...
  4. D

    Position of a charge (out of 3) with a net force of 0

    Homework Statement Point charges ##q_1=50 \mu C## and ##q_1=-25 \mu C## are placed 1.0 m apart. Where must a third charge ##q_3=20 \mu C## be placed so that the net force on it is zero? Homework Equations $$\vec F=\frac{1}{4\pi {\varepsilon}_0}\frac{|q_1q_2|}{r^2}\hat r$$ The Attempt at a...
  5. M

    Projectile Motion -- position and the highest point

    For 3 (a), I feel like I've gotten it down correctly, but comments would be appreciated! 3 (b), I'm not too sure about; could anyone please give a thorough review and point out mistakes if there are any? Number 4, I have no idea where to even begin. I've spent nearly an hour brainstorming, but...
  6. bryan goh

    Calculating Equations of Satellite Motion for Scientists

    how to calculate equations of satellite motion because I just thought to make it
  7. I

    Obtaining position in a dipole field

    Hi all, Consider one has a magnetic dipole, the field given by: \begin{equation} \vec{B} = \frac{\mu_0}{4\pi}\left(\frac{3(\vec{m}\cdot\vec{r})\vec{r}}{r^5}-\frac{\vec{m}}{r^3}\right) \end{equation} where we can take $$\vec{m} = m\hat{y}$$. Let us say we have the a magnet vector which is...
  8. N

    Velocity from position vector in rotating object

    Homework Statement I am trying to solve for change in velocity for the center of a rim with respect to the contact patch of a tire that has some degree of camber. The equation finalized is shown in the image below, equation 2.6. http://imgur.com/a/oHucp Homework EquationsThe Attempt at a...
  9. Sophrosyne

    B Measuring momentum and position in particle colliders

    When we look at those pictures of colliding particles in particle colliders, we see a large collection of curves and lines radiating out from the point of collision, representing the new particles which have been created. So two questions about this: 1) Why are these acting like particles in...
  10. S

    What magnetic position sensor to choose?

    I want to record the displacement of a small magnetic ball moving sideways across the face of the sensor. I've had a close look at AMS's catalog of magnetic position sensors and I'm not sure how to choose one. If I'm working with a movement range of <5mm and want a resolution of 5-10μm, and...
  11. Pushoam

    Kinematics 4 -- Calculate the velocity from the position versus time graph

    Homework Statement Homework Equations vav = total distance traveled/ total time taken The Attempt at a Solution I have a problem in part c . How am I supposed to solve it? Is there any standard way to solve it?
  12. percussive

    Which professor position would you select?

    For a job position: 1. Adjunct professor at MIT 2. Associate professor at a 4th tier university
  13. V

    Finding out force from a relation of position

    Homework Statement A particle of 1kg loves along x acid such that it's position x varies with time t as x =t(t-1)(t-2) m find the force exerted on the particle at t=0,1,2 Homework Equations Just given that position x varies with time t as x=t(t-1)(t-2) The Attempt at a Solution After opening...
  14. P

    Clarification of the motor rotor position

    I was referring to the following statement in the document which confused me and also attaching the document for your reference. "First, we need to know the rotor position. The position is typically related to phase A." How the above statement is true. Please help me to understand. I am...
  15. R

    Potential energy vs position curve

    Can a potential energy curve be vertical ?
  16. zonde

    B Photon Position: Is It Less Classical Than Massive Particles?

    I am puzzled by that statement. I do not intend to question the statement that "photon doesn't admit to define a position observable". My confusion is with the conclusion that photon is less "classical" because it does not have position observable as I can reach only weaker conclusion that...
  17. david2

    Chess position computers cannot solve

    there was a post here on PF about a chess position created by mathematics professor Sir Roger Penrose which computers could not solve. unfortunately the thread was locked so I made a new thread. < Mentor Note -- this thread is different, so the re-post is okay > it was the following position...
  18. sunnyday

    Suppose the position of an object is given by a vector

    Homework Statement Suppose the position of an object is given by r⃗ = (3.0t2i^ - 6.0t3j^)m. Where t in seconds. Determine r⃗ at time t = 2.5 s. Express your answer using two significant figures. Express your answer in terms of the unit vectors i^ and j^. Homework Equations plugging in 2.5...
  19. Charly

    B Why Do Bodies in Free Fall Change Position?

    Why do bodies in free fall change position relative to each other? For instance in a vacuum with no external forces why can an apple fall towards the surface of the earth? If these objects aren't accelerating then are they considered at rest? And in what sense of the term 'rest'. I think I can...
  20. A

    SN1 Rxn: is hyrdride shift major product or the LG position?

    Homework Statement So LG is on 2° position, and you have a hydride shift. So you form one product on 2° and one product on 3°. Which product will be major which will be minor? Homework Equations none. The Attempt at a Solution I know hydride shift will be more major than a methide shift...
  21. awholenumber

    B Some doubts about functions.... (changing the independent variable from time to position)

    Functions are pretty simple things , they just express a relationship between two different quantities How do i express this function in terms of y(x) = something ?
  22. C

    MCNP : spatial position of interactions

    Hi, I'm new in this forum and I have a question about MCNPX. I would like to determine the position of each interaction between photons and matter (specially by Compton scattering.) And I would like to know how much energy the incident photon gave to the electron. Is it possible to do that with...
  23. Y

    Buoyancy: 3 solid things have a different position in the water

    Homework Statement There is three things P, Q, R. The density of P is 2000 kg/m3, Q is 1000 kg/m3, R is 2500 kg/m3. If all of them are put into the water having density 1000 kg/m3, the correct position of the things are shown by following picture ... [PLAIN]http:// Homework Equations When ρ...
  24. E

    Other Postdoc Position: Finding a Job in Data Science

    Hello all, I was looking for a position in data science for a while, but I need time to develop the skills and experience since I have non. So, I was thinking to do another year as postdoc in a university in Canada or US or Europe in wireless communication to survive financially while...
  25. entropy1

    I Why is momentum the Fourier transform of position?

    Apart from the fact that it is, what is the physical significance of the fact that you can get the momentum distribution of a particle by taking the Fourier transform of its position distribution?
  26. M

    How Do You Calculate Acceleration at t = 1/1.1 sec from the Given Equation R(t)?

    Homework Statement All numerical constants are in the appropriate units, so that R (t) in units of meters, and a = 3.1 sec-1. What is acceleration size (in meters per second ^ 2) t = 1 / 1.1 sec? Note: When calculating sin (at), make sure the computer is in radian mode. Homework Equations...
  27. D

    Stargazing Apparent vs actual position of stars

    When we ‘see’ the Sun, from here on Earth, what we are actually seeing is the Sun as it was over 8 minutes ago when the light we currently observe first embarked on its journey towards us. In that time the Sun has in fact arrived at a position about two degrees east of the place it now appears...
  28. H

    Rotating rod returning to its initial position

    Homework Statement A uniform rod (mass 'm', length 'l') held horizontally above the ground. It is released from its supports and struck vertically upwards at one end. With what impulse should the rod be struck if it is to return to exactly its starting position and orientation? Homework...
  29. R

    I Integrating a curve of position vectors

    I'm looking at different ways to express the derivative a curve, like circular and tangent/normal components. Is there no such way that let's you express a vector integral in terms of information from the vector you want to integrate?
  30. J

    B Rotating Disks: Particle Movement & Spin

    When we rotate a disk, can this process be fully explained by looking worldlines of the particles the rotating disk is composed of, hence their x,y,z,t position "as time passes", or do particles have some kind of "facing direction", hence also spin(not the quantum mechanical notion of spin)...
  31. Y

    Is a position time graph and a displacement time graph the same?

    Please tell ?
  32. B

    Can I acquire the shaft position of my motor using my VFD

    The project I am working on is to design the control system for a shock dynamometer. I am using Labview and communicating to the VFD using Modbus. The shock dyno will look a little something like this; So one of the main objectives in my project is to produce a plot as seen below; The...
  33. J

    B Does an electron's position collapse when measuring g factor?

    https://link.springer.com/chapter/10.1007/978-3-540-39664-2_1 http://iopscience.iop.org/article/10.1088/0031-8949/1988/T22/016/pdf In these two experiments done back in the 80's, electrons were trapped inside a penning trap for long periods of time. They were measuring the ratio of the magnetic...
  34. davidge

    I Position Operator Action on Wave Function: $\psi(x)$

    Would the action of the position operator on a wave function ##\psi(x)## look like this? $$\psi(x) \ =\ <x|\psi>$$ $${\bf \hat x}<x|\psi>$$ Question 2: the position operator can act only on the wave function?
  35. LarryS

    I Why no position operator for photon?

    Apparently, in QM, the photon does not have a position operator. Why is this so? As usual, thanks in advance.
  36. A

    Automotive Calculate the position for a linear acutator

    Hi everyone! So I'm working on project where I have to design a hinge system for a hard lid that is fitted onto the back of a pickup truck. In this system, I will be using 2x linear actuator(s) that will need to lift a total weight of roughly 95kg. At the moment, I've got a selection of 600N...
  37. M

    I Position and Momentum are random variables in QM?

    A paradigm shift for me occurred when, I now realize, that position and momentum are random variables in QM. As such, it does not make any sense to say things like "take the derivative of the position with respect time". Instead QM has the position and momentum operators which operate on the...
  38. S

    Is the US abandoning its position as a science superpower?

    Hi everyone! I was reading another thread under Career Guidance and have found the following (credit from @Crass_Oscillator): "China is aggressively attempting to displace the US as the world's scientific superpower, and the US is aggressively attempting to abandon it's scientific superpower...
  39. B

    Lorentz Transformation and position of the object

    Homework Statement Reference frame S' moves at speed v=0.94c in the +x direction with respect to reference frame S. The origins of S and S' overlap at t=t′=0. An object is stationary in S' at position x′ = 140 m . Part B What is the position of the object in S when the clock in S reads 1.3 μs...
  40. C

    Hilbert Dynamics in choosing position in BM/MWI

    In General Relativity. Gravity is caused by curvature of spacetime. In MWI and Bohmian Mechanics.. the position observable and position preferred basis is chosen. There must be a non-zero energy or some kind of dynamics that would lock the particular Hilbert space vectors into those special...
  41. B

    Position vs. time graph and the derivative

    So let's assume an object moves along a straight line relative to some fixed origin. Clearly we can study this motion with the help of a position vs. time graph which shows how the position varies as time goes on. Now, as far as I understand, the slope of this graph at any time t gives the...
  42. S

    Potential Energy vs. Position Graphs

    Homework Statement A particle has the potential energy shown in the figure. (Figure 1) What is the x-component of the force on the particle at x =5, 15, 25, and 35 cm? I'm stuck on finding the Fx at 25 & 35 cm.Homework Equations F = -du/dx 100 N = 1J/cm The Attempt at a Solution Slope...
  43. AdrianMachin

    Finding third charge coordinates in an equilibrium position

    Homework Statement Here are the problem statement and the solution. I'm stuck at where the book suggests the formulas for the x and y coordinations (highlighted in yellow) of the third charge. Any explanations or proof on how they came to the conclusion for the third charge coordinations would...
  44. Philosophaie

    Calculate the Apparent or OF Date from J2000 position

    I am trying to change from J2000 to Apparent positions. Astronomical Algorithms by Jean Meeus addresses but does not give a correct answer. VSOP87 gives the Apparent or Of Date positions in VSOP87C and VSOP87D but I need to calculate directly from J2000. How do I do this?
  45. Yovanna

    Velocity and position of the boat

    Homework Statement A boat leaves the dock at t=0 s and heads out into the lake with an acceleration of 2m/s^2i.A strong wind pushing the boat, giving it additional velocityof 2m/si+ 1m/sj. (a) What is the velocity of the boat at t=10s? (b) What is the position of the boat at t=10? Homework...
  46. Kara386

    Commutator of position and momentum

    How would ##[p_x, r]## be expanded? Where ##r=(x,y,z)##, the position operators. Do you do the commutators of ##p_x## with ##x, y,z## individually? So ##[p_x,x]+[p_x,y]+[p_x,z]## for example?
  47. matthewh806

    Admissions Applying for a European PhD position with a UK MPhys degree

    Hey, I'm looking for a bit of advice with regards to applying for a PhD program in Europe. As a bit of background: I graduated from Durham University in 2013 with a 1st class MPhys in Theoretical Physics. My thesis (which contributed to half of the grading in the 4th, masters year) was focused...
  48. doktorwho

    Find the position of equlibrium

    Homework Statement From the diagram below find the position of the man (##x##) if the system is in balance. Total length is ##L## and the man is distance ##x## from one end. Homework Equations 3. The Attempt at a Solution [/B] I know that the system must be in balance if all the torque and all...
  49. F

    I Position representation of the state of the system

    Hello Forum, My understanding is that the state of the system is ##|\Psi>##. We can take the inner product between the state ##|\Psi>## and the eigenstates of the position operator ##\hat{x}##: $$<x|\Psi>=\Psi(x)$$ The function ##\Psi(x)## is the wave function we are initially introduced to in...
  50. Crush1986

    Position Operator in Momentum Space?

    Homework Statement So, I'm doing this problem from Townsend's QM book 6.2[/B] Show that <p|\hat{x}|\psi> = i\hbar \frac{\partial}{\partial p}<p|\psi> Homework Equations |\psi(p)> = \int_\infty^{-\infty} dp |p><p|\psi> The Attempt at a Solution So, <p|\hat{x}|\psi> = <p|\hat{x}...
Back
Top