# Search results

1. ### I Odds ratio and percentages... absolute beginner

Imagine that the chances in the USA of adult men having GAD are on average 1 in 100. But what of the subset of adult men who already have MD? What are the chances that such men will have GAD as well as MD? An odds ratio tells us about the increase in the chance that such men will have GAD...
2. ### Suggestion Floating menu bar

What is the purpose of that floating menu bar on top, it is quite cumbersome for me on my small screen with its big writing. You know in the 90s there were frames on every website and we got rid of them because they were universally hated. Now that we all have wide-screen computers and...
3. ### Finding the force of repulsion between two point charges

Hello! So this is going into physics because it is a physics problem, but it is maths that is the real problem. So if you came here to help someone with physics and not maths I'm sorry. 1. Homework Statement Find the force of repulsion between two point charges of +1C and +3C if they are...
4. ### B Vocabulary: What do you call spinning on the opposite axis?

So imagine you have two disks, and from your perspective one is spinning on its vertical axis and the other one is spinning on its horizontal axis. What do you call that? And what would it mean to "spin at the opposite polarity" if such a sentence makes any sense at all? Thank you! Sorry if...
5. ### Find the mass of a metal block with heat capacity 60JK

Homework Statement A metal block of heat capacity 60 J K -1 loses 1MJ of heat energy to its surroundings. Find the decrease in its temperature. Homework Equations Q = m c Δ θ Heat energy added = mass x specific heat capacity x rise in temperature heat energy lost = blah blah blah x drop in...
6. ### Finding the angle of refraction

Homework Statement The refractive index of diamond is 2.42. A ray of light passing from the inside of a diamond into air makes an angle of incidence of 20 degrees. Find the angle of refraction. Homework Equations n = refractive index aNd = 2.42 (my book said the speed of light in a vacuum and...
7. ### Finding distance of image from mirror given focal length

Homework Statement An object is at a very large distance from a concave mirror of focal length 40cm. Find the distance from the image to the mirror. Is the image real or virtual? Homework Equations 1/u + 1/v = 1/f The Attempt at a Solution [/B] 1/u + 1/v = 1/40 The image has to be real...
8. ### Finding apparent depth real depth and refractive index

Homework Statement refractive index = 1.33 (water) real depth = 10m Homework Equations refractive index = real depth divided by apparent depth The Attempt at a Solution I'm going to call apparent depth X 1.33 = 10/x So I multiply 10/x by 10 so that i have x and 1.33 x 10 is 13.3... that's...
9. ### 1/u + 1/v = 1/f

Homework Statement u= distance from the object to the mirror v = distance from the image to the mirror f = focal length I don't understand what they are talking about and I would like to 2. Homework Equations If the image is real 1/u + 1 v = 1/f If the image is virtual 1/u - 1/v = 1/f The...
10. ### Expressing measurements in SI units

Homework Statement I am given some measurements and I am supposed to express them as standard SI units. I can't find any examples of this done online or extra practice exercises to help me. I am probably googling the wrong words. I have been out of school for quite a while and I don't know what...
11. ### Virtual image on the perpendicular

Homework Statement The book ("Real World Physics") says A virtual image in a plane mirror is on the perpendicular from the object to the mirror Homework Equations I know that the normal line is perpendicular to the surface of the mirror And I know that the angle of the incidence and reflection...
12. ### Moving things to the other side of the equals sign

Homework Statement A 20gram bullet it shot out of a 10kg gun at a speed of 300 m/s What is the recoil speed of the gun (I am putting this in maths rather than physics because I understand the physics part it is just basic maths of using an equation that I am stuck with) Homework Equations G=...
13. ### What to do with a mathematic equation

Homework Statement A ball is thrown upwards at a speed of 29.4m/s Where is it 4 seconds after being released. Homework Equations d[/B]=v0t+1/2at2 So I understand what the letters all stand for because that information is explained, but I don't know what to do with it. The Attempt at a...
14. ### Free certificates?

Of two minds about whether to put this here or in Biology / medicine Hello all, I am planning on applying for physiotherapy as a mature student and any proof I can get of my aptitude for study would be so helpful. I already have a few certificates from courses over the last few years, but the...
15. ### Removing the amydala of snoring children!?

I think this is a case of an inebriated translator.. Or someone whose attention is lacking due to a problem with snoring and who needs their amygdale removed.. The book is Attention: Theory and Practice - by Addie Johnson and Robert W. Procter. I am reading it in Spanish translation, I don't...
16. ### Binary, base 2, bits, and coin flips

I am studying psychology and have always been awful at maths (I think it's because I don't have much working memory), I am coming at this as a complete beginner. It is relevant to the Information Processing model of psychology. _____ The book says: Imagine you throw a coin once.. once it lands...
17. ### How attention affects perception - Mach and Stumpf

This is a bit of a logic problem that should be figure-outable from the information At the turn of the last century there was a debate about whether attention increased the perception of something by increasing the clarity of that one thing, or by decreasing the clarity of everything except...
18. ### Aristotle - Efficient cause

http://plato.stanford.edu/entries/aristotle-causality/#FouCau I'm confused by this The efficient cause: “the primary source of the change or rest”, e.g., the artisan, the art of bronze-casting the statue, the man who gives advice, the father of the child. So.. the efficient cause of an exam...
19. ### Why can I feel hiccups in my left arm?

Also, when I swallow a tablet with a big gulp of water I can feel it in my left arm too. Usually just above the elbow. I'm guessing, because it's the left side, it has something to do with my heart. I'm not hypochondriaking, I'm just curious.
20. ### Math help? Concurrent schedules of reinforcement

In concurrent schedules of reinforcement [a mouse has a choice between pressing a button to get sugar or pressing it to get cheese], the choice or preference between the two alternative response is calculated by the relative rate of response and is represented by the quotient: Ra ___ Ra + Rb...
21. ### Difference between a marker and a secondary reinforcer?

A marker is something that makes up for the delay of reinforcement by signalling to the subject "reinforcement is coming" For example saying "good dog" before giving your dog a treat. Secondary reinforcement is when something becomes reinforcing / causes pleasure through it's association with a...
22. ### What's delta doing here?

I last studied maths in school 10 years ago and we never used any Greek letters. 1. Homework Statement Talking about contingency in classical conditioning in psychology. The sum is a calculation that people and animals seem to do in their heads to work out the probability that two stimuli...
23. ### Supression ratio in classical conditioning

I think that if you're good at maths you'll be able to help me without having heard of this before, assuming you know about classical conditioning it's explained here; http://brembs.net/classical/suppress.html The measure of the extent to which the CS suppresses responding is called the...
24. ### Poking someone falling into a black hole with a stick

Please excuse me for being a complete and utter pleb, my meager knowledge of Leonard Susskind's holographic principle comes from the second episode of the documentary "Through the Wormhole" (which is available online but I won't link to in case it is copyright infringement?). He talks about...
25. ### Darwin on the inheritance of learned characteristics

That should be Lamark! That should be epigenetics! Right? (I remember reading something about breeding rats with a fear of cherry blossom scent) I thought that Darwin rejected all this, but maybe I am confused with how his work was later interpreted by other people in light of Mendel...
26. ### Why does it cause problems to be missing an X chromosome

http://en.wikipedia.org/wiki/Turner_Syndrome As in being X0 rather than XX or XY I thought that the X you get from your mother and the X you get from your father all coded for the same things. I wouldn't have imagined anything would happen rather than all of the recessive genes on the X...
27. ### Epistasis clarification - congenital deafness

Can you help me understand this please? Quote is from “Fundamentals of Psychobiology” published by Sanz and Torres (Fundamentos de Psicobiología) Quotes in italics: Epistasis consists of the interaction between genes which determin characteristics in such a way as that one gene masks the...
28. ### Medical Why aren't hunger thirst and (the need to) sleep considered reflexes?

A reflex is an automatic and involuntary response of a living thing to the presence of a stimulus. A reflex is usually a movement, but it can be the activation of secretion in a gland. Is it because there is no particular stimulus? Not having eaten, drank, slept for a while is not considered a...
29. ### Poligraph tests test resistance or conductance?

Homework Statement Question: "What does a polygraph test measure; skin resistance or conductance?" To me this is two sides of the same coin and it seems it must be measuring both. Homework Equations The Attempt at a Solution I thought that the person is acting as a resistor so I wrote...
30. ### Types of experimental manipulation in Social Psychology

The only information my textbook gives me is this: We classify experimental manipulations into three broad types, depending on whether they involve variations in the physical, social, or instructional features of the experimental context. Social manipulations are usually dependent on...