hand Definition and 468 Threads

  1. R

    Why Did Android Lollipop Remove the Hand Gesture Feature for Selfies?

    In the recent android version which is Lollipop the feature of palm showing to mobile to take a selfie after 2 seconds has been removed or I am not able to spot it clearly? There is also a space left in between camera reversal and some beauty thing. Earlier that was there in Kitkat version. Why...
  2. P

    What is the Direction of Magnetic Field Lines?

    This is completely confusing me, please help. The word that is giving me problems is "direction". The text talks about the "direction of the magnetic field lines" . As I understand it, the fied lines curve around a straight wire. So you can only have two directions, clockwise or anticlockwise...
  3. Eric Diaz

    Force exerted on the palm of your hand by a beam of light

    Compute the force exerted on the palm of you hand by the beam from a 1.0W flashlight. (a) if your hand absorbs the light, and (b) if the light reflects from your hand. What would the mass of the particle that exerts that same force in each case would be if you hold it at Earth's surface? On...
  4. B

    Battery and torque in a hand drill

    Hey, I have a project where my group needs to design a drill. I am wondering if anyone here knows how to calculate the torque we get from 3 AA-batteries on 3.6 V (10.6 V together). How does it work? It just needs to assemble furniture, so we don't need very much force on it. Do you know what...
  5. H

    Fleming left hand rule or right hand grip rule?

    Homework Statement Homework EquationsThe Attempt at a Solution Answer is C? But why?
  6. S

    A question about the right hand rule

    Hey everyone, I was hoping you could help me solve a little problem. I'm having a little difficulty understanding why the right hand rule works for determining the direction of the magnetic field. I've found a similar question posted here...
  7. G

    Scalar product using right hand rule ?

    Homework Statement Refer to solution II , the author used the scalar analysis( dot product) to get the direction of moment ...IMO , this is incorrect ... Only cross product can be determined this way . correct me if I'm wrong . Homework EquationsThe Attempt at a Solution
  8. G

    Using Right Hand Thumb Rule to Determine Resultant Force

    the moment is r X F = rFsin tetha which means r is projected to F , am i right . If so , then the resultant force should point downwards( by using right hand thumb rule) , am i right?
  9. O

    Force of hand on block = F of block on hand, not adding up?

    Lets say I apply a force of 20N to a 10kg block on a frictionless table. Then the acceleration of the block is F= ma = F/m = 2m/s^2 = a. Then, supposing I am standing on the ground with real world friction such that I am not accelerated in the opposite direction when I push the block that is...
  10. Erich1

    Why do I feel Pressure on the palm of my hand?

    When I lower on object towards my palm (e.g. a pendulum on a long string, or a small metal object, etc) I feel a very subtle, but distinct sensation on the palm of my hand. What could be causing this? I don't think it is heat from the other hand. Can an stationary object produce a subtle...
  11. M

    Magnetic Field -- Some help with the right hand rule please

    Homework Statement A magnetic field of 0.0200 T (up) is created in a region. a) Find the initial magnetic force on an electron initially moving at 5.00 x 10^6 m/s (N) in the field. b) What is the radius of the circular path? Make a sketch showing the path of the electron. Homework...
  12. E

    Earth's Orbit & Fleming's Left Hand Rule

    Please forgive me as I am inquisitive enough to be dangerous. Question First, Thoughts Behind It: * How much validity is there in the application of Fleming's Left [edit: RIGHT!] Hand Rule towards the orbit of the Earth around the Sun? * I saw that NASA recognizes this but they seem to sort...
  13. EJC

    What Are Your First Hand Experiences Studying for the PGRE?

    I'm taking the PGRE in about 3 months and haven't really began studying. There's loads of study tips out there already, but I'm looking for any first hand experience anyone has had with taking/studying for the PGRE. I've found that no matter what tips you can find, first hand experience is...
  14. A

    Fleming's Left and Right Hand Rules

    Hi, I was wondering if anyone has any advice on when to use FLHR and FRHR in the Edexcel A - Level Physics, as I'm mixing them up in questions. Thanks, Abby
  15. J

    Book sandwiched between your hand and table

    Hi, I have been working on this problem for a while: You place a book flat on a table and press down on it with your right hand. The hand-to-book and table-to-book coefficients of kinetic friction are 0.48 and 0.43 respectively. The book's mass is 1.14 kg and your downward push on it is 9.70 N...
  16. S

    Integration by parts, just need a small hand

    Homework Statement I'm going to cut from the initial part of the problem, which I am confident is good to go, and cut straight to the antiderivatives. Homework Equations All antiderivatives are to be integrated on the interval from 0 to π/18 (I1) = -1/9 cos 9x - (I2) (-2/27 * cos3(9x)) + (I3)...
  17. T

    Calculating the Probability of a 5 Card Hand with Cards from Exactly 2 Suits

    Homework Statement What is the probability of getting a 5 card hand where the 5 cards are from exactly 2 suits Homework Equations nCr = n!/(r!(n-r)!) The Attempt at a Solution There are two possible cases where the 5 cards are from 2 suits, case one is 4 are from one suite and 1 is from...
  18. B

    Draw Nyquist Plot By Hand: Learn How to Determine Stability

    I am trying to understand how to draw nyquist plot. Lets say the transfer function is Subbing in jω for s, ***Note: should be (jw)^4 , (jw)^3, (jw)^2 Then separating the Real and Imaginary part, So when w = 0, in the nyquist plot it is infinity w = infinity, it is 0 Imaginary intercept is...
  19. B

    Stokes's Theorem and the Right Hand Rule

    Homework Statement For \mathbf{F} = y \mathbf{i} - x \mathbf{j} + 4z \mathbf{k} evaluate the surface integral of (\nabla \times \mathbf{F}) · k over the 2D surface of the disc x^{2} + y^{2} \leq 4, z = \frac{H}{2} Homework EquationsThe Attempt at a Solution I am unsure of my answer to this...
  20. minimario

    Unsure About the Right Hand Rule? Get Help Here!

    Homework Statement Homework Equations Right Hand Rule The Attempt at a Solution I can get the magnitude, but cannot get the directions from the RHR. Can somebody make video/explain? Thanks!
  21. M

    Flat plate heat exchanger - Hand calculations help

    I am designing a flat plate heat exchanger for a project and I am not sure where to start with the hand calculations, specifically the LMTD and E-NTU methods, also how to work out the parameters which i will need to complete these methods such as area and number of plates. My deadline is soon...
  22. R

    Why Is the Right Hand Rule So Confusing?

    I'm just really confused with this right hand rule even though it seems like it's supposed to be pretty simple and obvious. I know the rules, however it doesn't really work for me. Maybe I'm doing something wrong. I have three examples I'd like to cover which are related to each other, I hope...
  23. W

    Right Hand rule-Why is it possible

    Homework Statement I understand that the right hand rule is a convention to give the movement of charged particles around a current carrying wire, but why is it possible to have a standard convention? Why can't the charge particles move either way? Why does the movement of particles in that...
  24. Alex Mercer

    Correct electric charge/current flow & left/right hand rule?

    Hello there, people! I am quite new here; in fact, this is my first post. I am quite strange to this place. Feeling kinda welcome, though. Okay, so short to the point. I am an 8th grader, and my school just started teaching us about electricity. Well, the basics. I knew much about it, much...
  25. O

    Hand drawn ray tracing through an optical system

    Hi, I am familiar with drawing rays through a lens. But when a few lenses are put together, things become confusing to me. For example, if a first positive thin lens at 0 forms a real image 10cm away, what would happen when we put a second positive thin lens, say at 5cm along the optical...
  26. J

    MHB Left hand and right hand limit at infinity

    Show that $\lim_{{x}\to{0}}$ $\frac{1}{x}$ does not exist? Please tell me how to make LHL and RHL for this? Explain me all steps used?
  27. P

    Does acidity and hydrogen bond strength go hand in hand?

    More acidity means more electronegativity, and more electronegativity means more dipole moments. I observed that liquids with low dipole moments (bases) often have lower density and surface tension, but not necessarily hydrogen bonds. To contradict it, acetic acid have a low surface tension but...
  28. Pull and Twist

    MHB Calculus Question: Sketching a Function by Hand

    Hey all, I'm currently working a Calculus problem that requires me to sketch f(x)=(3x-1)/(x-1)^2 without using a calculator. Part A: Requires that we find; i. x-intercept: f(0)=(3*0-1)/(0-1)^2=-1 So f(0)=-1 ii. y-intercept: f(x)=0 therefore; 3x-1=0 or x=1/3 So f(1/3)=0 iii. horizontal...
  29. G

    Find Forces on Hand and Arm Holding a Ball

    Homework Statement When an object is static (not moving), forces and moments must balance to zero. A moment here is defined as the force applied to an object multiplied by the distance from the point of rotation (torque). A simple way of thinking about moment balances is to consider a seesaw...
  30. T

    Could a person do this? -- Push a cruise ship by hand

    I was watching a program on the worlds largest cruise ship, the Oasis of the Seas. It displaces 243000 tons. They we're discussing the sophisticated maneuvering systems and I got to thinking. Let's say the ship is docked, within a foot of the dock and untethered. If I sat down with my legs...
  31. T

    Ti-89 Limit of Integral undefined BUT it is 4 both by hand and Mathematica

    I am giving the following input to Ti-89 Titanium: limit(S((2 x cos(100 x Pi x t)+2 x sin(10 x Pi x t))2 ,t,-t1,t1)/(2 x t1),t1,inf) where S is the integral symbol, Pi is π = 3.14, x is the multiplication symbol and inf is the infinity symbol The TI-89 answer is undef If I do it by hand it...
  32. D

    MHB Card Hand probability question

    Working on a problem and unsure how to set it up. Feels similar to other I believe is solved correctly. Any help appreciated. Solved problem: 52-card deck, 13-card hand, odds of getting 4 of a kind. For this I used a Hypergeometric Distribution with the following parameters: 1) population size...
  33. K

    Right Hand Rule & Conventional Current: What is Correct?

    Homework Statement I have a question that involves a wire XY (X moving down the page to Y) moving to the right of the page at right angles to a magnetic field that acts out of the paper. The question then asks me which end of the wire will become positively charged. The textbook uses...
  34. ranju

    Right hand thumb rule curling fingers

    according to RHR , the curled fingers show the direction of magnetic field or flux & the thumb gives the direction of current.. but I am confused about the curling of fingers.. I want to make my doubt clear by the pictures I attached.. In bothe first & second picture , the magnetic field is in...
  35. R

    Good Reference Books for Mechanics, Nuclear, Optics & More

    I'm looking to reduce the amount of books I have, but I'd like to get a few references references books to replace them. I'd like a set of books that encompasses everything from mechanics, nuclear, optics, and solid state, to ,basic lab electronics, astronomy, quantum, and their mathematical...
  36. E

    Bernoulli trial summation by hand

    Homework Statement Show that the expected number of successes in n Bernoulli trials w probability p of success is <x> = np Homework Equations The Attempt at a Solution So I get the right answer which is this: E\left( x\right) =\sum _{x=0}^{n}x\left( \begin{matrix} n\\...
  37. L

    Hand Moldable Plastic: Find Material for Room Temp Shaping

    Hi, I am looking for a material that molds/gets shape with hand at room temperature and does not separate! Does such a material exist? (By the way I am do not have physics background!) Many thanks for you help :) Leila
  38. Tesladude

    Help -- car stereo is acting up with hand made amplifier

    I am adding 2 extra rear speakers in my jeep, I have some rca cables comming from the rear speaker pre-amp outputs from the back of my pioneer stereo. My plan which works beutifully is a dc-dc boost module bringing the cars 12v up to 20 for the main amplifier. The main amp is a 2x25...
  39. M

    Impact of trolley - hand calculation method

    Hello, Been a while since I posted on here, nice to be back :) . I just want some pointers as to the methodology for an impact load case that I'm looking at. I've attached a very basic sketch of a trolley which is traveling at a known velocity and impacts a rigid structure at it's base. What...
  40. Evanish

    Could superman fit his hand around a Basketball?

    I know that you probably get tired of weird questions like this so I apologize in advance. I was thinking about length contraction in special relativity. I was thinking if superman was moving towards a basket ball at close to the speed of light when he passed it from his frame of reference it...
  41. G

    Can Fleming's Right Hand Rule Be Used When Magnet Moves Parallel to Coil?

    Can I use Fleming's right hand rule to determine the direction of current when a magnet is moved into a coil(s) of wire? I am finding it difficult because the magnetic field and movement are parallel instead of at right angles. If not, does this mean I am only allowed to use it when a wire...
  42. D

    Differential equation right hand function

    Homework Statement The question specifies the auxiliary equation given is (D^2 + D - 2) = (e^x)/(x) the method of variation of parameter must be used to find the particular solution to the right hand function. then finally the general soultion should be stated.Homework Equations variation of...
  43. M

    MHB Hand Computing: Evaluate $\sum_{k=1}^{2013}f(k/2014)$

    Define: \[ f(t) := \frac{7^t}{7^t + \sqrt{7}}. \] Without the aid of a computer or calculator, evaluate: \[ \sum_{k=1}^{2013} f \left( \frac{k}{2014} \right). \] (Please show the work.)
  44. M

    Left hand side of the Schrödinger equation

    The time dependent Schrödinger equation is: i\hbar\partial_{t}\Psi=\hat{H}\Psi Does it mean that the operator i\hbar\partial_{t} has the same eigenstates and eigenvalues as any Hamiltonian?
  45. T

    What Direction is C? Apply the Right Hand Rule

    Homework Statement If C = A × B, A points up, and B points south, which direction is C? Select one: a. west b. up c. north d. down e. east Homework Equations The Attempt at a Solution i used the right hand rule and got east as the solution could i have a little verification...
  46. 0

    Shooting a .45 caliber hand gun on the moon launches you a mile?

    Shooting a .45 caliber hand gun on the moon "launches" you a mile? My co-worker and I were having a discussion about an activity that he did while at a teachers math conference. The activities was to rate the importance of objects. There were 15 objects and you are stranded on the moon 200...
  47. adjacent

    Fleming's left and Right hand rule

    Homework Statement Not a Home-work problem,just a doubt.Since this is a school doubt,I will post here. Fleming's left and right hand rule Why do we use two hands for the same thing?Can't we just use one hand? Why is it different? I have tried searching Google but could not get an answer...
  48. C

    Taking good notes fast - on computer? By hand? software?

    Hi, So I'm studying Chemistry and biology and I'd like to hear your advice on notetaking. Perhaps some of you can help me find some good software for taking notes faster? First let me paint the picture for you: Whenever I learn a new subject such as electrochemistry or Entropy etc., I like...
  49. L

    Right hand rule - Magnetic field

    Homework Statement Conventional current flows in a ring in the direction indicated in the diagram (if you stand at location A, on the +x axis, and look toward the ring, current flows clockwise). At each of the locations labeled by a letter, use the right hand rule to find the direction of...
  50. N

    Calculating Temperature Increase From Hand Rubbing Work

    Homework Statement Rubbing your hands together warms them by converting work into thermal energy. If a woman rubs her hands back and forth for a total of 10 rubs a distance of 7.50 cm each and with a frictional force averaging 45.0 N, what is the temperature increase? The mass of tissue...
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