Stupid Definition and 282 Threads

  1. P

    Undergrad Can Differentiation from First Principles Be Applied to Trigonometric Functions?

    Yo. Curious about two things.. First, is it possible to use a method such as differentiation from first principles (the whole lim_{\delta\rightarrow0}\[f(x+\delta)-f(x)]/\delta thing) to differentiate trigonometric functions? Or is everyone stumped with memorizing them? (I'm curious about...
  2. F

    Undergrad Few stupid questions about polar curves and stuff

    Few stupid questions about polar curves and stuff... Okay, here's the first dumb question. I have to find the tangent line where r=2-3sin(T) at the polar point (2,pi). To find the slope, you just take dy/dx, and I come up with 2/3. I know that part is right. T=theta (I know it's spelled...
  3. T

    Baseball Velocity and Components: Solving for Final Velocity and Height

    I'm not quite sure how to get started on this problem... a baseball is struck by a bat, and 3 seconds later it is caught 30m away. now the questions ask for it's final velocity, it's angle as it left the bat, the greatest height it reached, and the X and Y components of it's velocity as...
  4. B

    Graduate Can Different Wavelengths Measure Particle Momentum and Position Simultaneously?

    The Uncertainty Principle says, in so many words, that if you use a shorter wavelength of light you obtain a more accurate value for the position of the particle, and that if you use a longer wavelength you obtain a more accurate value for the momentum. Of course the more accurate you are with...
  5. P

    How Does Momentum Affect a Moving Toy Truck When a Brick is Dropped on It?"

    a 1.5 kg brick is dropped vertically onto a 2.5 kg toy truck, which is moving across a level floor at 0.80 m/s. With what velocity do the truck and brick continue to movie, after the brick has landed on the truck. i've dealt with only horizontal movements andd i haven't covered this yet in...
  6. C

    High School Does Weight Increase Impact Severity in Collisions at Constant Speeds?

    i was just watching gone in 60 seconds on television. in the movie an actor is standing on a platform and someone swings a crane's claw into him at approximately 15mph to knock him off the platform. this started an argument between my roomates and I about whether or not the weight of the claw...
  7. F

    Undergrad Understanding Integrals: Multiplying by a Constant Within the Integral?

    if you have \int_frac{y}{x}=int_L, if you multiply the LHS by c within the integral, is L multiplied by c within its integral?
  8. T

    Stop Judging: Breaking the Stigma of Asking Questions | Our Thoughts

    Let's face it, if you have to ask a question then that means you don't know the answer, right? So you must be stupid, right? Right?
  9. Math Is Hard

    Balancing Chemical Equations: Tips and Tricks for Frustrated Students

    As you can tell, not my favorite subject. I was going along fine just tinkering with these things and working them out until I started trying to balance this one: Ca3(PO4) + H2SO4 -> CaSO4 + H3PO4 The coefficients I have tried so far are: 2Ca3(PO4) + 3H2SO4 -> 6CaSO4 + 2H3PO4 so...
  10. D

    Why Does Cutting the String Change the Tension Ratio in a Pendulum?

    SO. a ball is suspended by a string from the ceiling, and held at angle theta to the vertical by another string that is attached to the wall nearby... the string attched to the wall is cut and the ball swings like a pendulum, at the farthest it is theta from the vertical on both sides...
  11. S

    High School Solve Calculus Question: Positive and Negative Cases for x > 1/3

    we just started our calc class, and our teacher gave us this question im sure it is really easy, and i don't know why i just can't get it analytically the question is solve 1 - < 3 solve for positive and negative case. x the positive value is easy, X> 1/3 . How would you...
  12. shintashi

    Graduate Is Cold Fusion a Feasible Energy Source or a Dangerous Concept?

    Over the past year, I've evaluated my own research and observations and matched them up with some statements from a pair of friends. One worked on a nuclear sub, and the other worked on an aircraft carrier. Both worked in the nuclear engine rooms. As I've been refining the concept of...
  13. P

    Stupid question looking for stupid answer

    Dozen of science site, offical or not, are saying that moon is always the same apparent size. Most of these site are explaining the perception of size as a simple legendary optical illusion. Some personnal experience lead me to believe that it was not! After about 6 month waiting, I finally...
  14. T

    I'll take the blame, but c'mon stupid is stupid

    I like to play with things. Magnets are so fascinating I buy them all the time. I know I should put my toys away when I'm done, but they are just a couple of small magnets so it shouldn't be a big deal. My girlfriend is a clean freak, she can't stand things not being put away. Last night I went...
  15. A

    Undergrad You guys are gonna think im either stupid or crazy

    nice title huh, ok now i know that by saying this I am getting the instant reputation of an idiot, believe me, i know about einstein's theory of relativity and the first 2 laws of thermodynamics, but believe it or not i have made a perpetual motion mechine. at this point, i bet most of you are...
  16. E

    Is Fruitarianism a Sustainable Diet for the Future?

    When I first heard of fruitarianism I thought it was a good idea. I haven't found information that says just eating fruits is insufficient to stay alive. Fruits taste better than vegetables. Now we see that vegetarians are idiots. Hehe, just kidding. I like the taste of meat, but I enjoy most...
  17. N

    Solving Algebraic Equations: Tips for Overcoming Common Mistakes

    Solving Algerbraiclly...Nevermind! It seems I always try a different section of the forums just as someone is answering my out of place one... Haha...
  18. W

    High School Understanding the Compton Effect: How Light Reflects on a Mirror Explained

    Could you explain me how does Light reflect on a mirror? I assume that Compton effect on electrons is the only way for light to come back to my eyes but in that case, there would be a change of frequency of the photon (and a change of color). Does it mean that it is not me in the mirror ...
  19. C

    Undergrad How is the distance between a line and a circle calculated?

    We're doing a bit about circles in Pure Maths at the mo and everything's fine about intersections etc until today the lecturer rammed up an easier eqt to tell if a line cuts a circle at 2 distint points or not. We had to show that the line 3y=x+5 cut the circle x^2 + y^2 -6x - 2y -15 in 2...
  20. A

    High School Understanding the Difference Between Deceleration and Deceleration Force

    is there a difference between decelaration and a deceleration force or are they just the same thing? thanx(an don't laugh)
  21. A

    High School How Much Weight Does Spray Paint Add to a Paper Rocket?

    hello! I'm new on this forum. I am currently building a paper rocket. Just a question (if you can please help): how much weight do you think spray paint or permanent marker will add to the paper rocket? Thanks in advance,
  22. Monique

    High School How to Solve for fF in K = fF/(1-fF) | Helpful Tips and Tricks"

    K = \frac{f_F}{1-f_F} OK, I feel like the stupidest person ever, but if I know K, how do I find fF? I even know the answer.. if K = 0.504.. fF will be 0.335.. which is 33.5%, the other fraction is 66.5%, which is 0.504.. Still can't figure how to solve the formula :(
  23. C

    University of Chicago Study: The Stupid are Outbreeding the Smart

    See http://neko.mi.org/~tawollen/humor/msg02033.html Regards, Carlos Hernandez
  24. M

    Why Rinse Hair With Vinegar After Shampoo?

    I was reading something and it said some people rinse their hair with vinegar after washing it with shampoo because shampoos are basic but it never said why they rinse it with vinegar. Do anyone know why they do that as i found it quite odd?
  25. P

    Amplitude and Intensity Relationship: Explained and Solved

    Stupid Amplitude...HELP! So I am working on some phys homework and I had a question about this problem: If the Amplitude of a sound wave is quadrupled, by what factor will the intensity increase? And I thuoght that the relationship between Intensity and amplitude was that Intensity is...
  26. T

    Has this ever happened to you? Or am I unique or just stupid?

    Has this ever happened to you? Or am I unique or just stupid?? I went to the refridgerator to get myself a drink of soda pop. Unfo rtunately there was no soda. I realized that when I got home from the store I had place the warm 2 liter bottle of Pepsi in the freezer. I opened the freezer and...
  27. dduardo

    Stupid Tech Lawsuits: Examples & Effects

    I have started this thread to show the stupidity in modern tech lawsuits and how it is affecting innovation and progress. Please post your stupid tech lawsuits. 1) Parents Sue School Over Use of Wi-Fi Network Aparently, the parents believe that Wi-Fi is hazardous to our health and are...
  28. D

    High School Would Jumping Up at the Same Time Affect Earth?

    if everyone in the world were to jump up at the same time would that affect the Earth in any way?
  29. D

    Hi, I'm in AP Calculus and I feel really stupid

    Hi, I'm in AP Calculus and I feel really stupid :( I feel really stupid because it's only the first week of school and I'm struggling with the review (I forgot a lot over the summer) I'm posed with these two problems (in addition to many other but I don't want to bore you all :))...
  30. M

    Undergrad Calculating the Size of the Universe

    well i know I am wrong somewhere so show me where... couldnt we calculate the size of the universe by taking the speed of light and the estimated age of the universe (14.5 billion years) and consequently use 14.5 billion light-years as a radius and put it into the old spherical volume...
  31. M

    IIRC Meaning: What Does It Stand For?

    I have been on the Forums for a long time, and I have seen a lot of acrostics, and abbreviations. But I just can't figure out what IIRC stands for . Can someone tell me please?
  32. C

    Ask a Stupid Quetion Get a Stupid Answer

    Woohoo, a brand new forum to post in! Just thought it didn't feel quite right without this here. So in the tradition of PF 2.0 ask a stupid "quetion" and get a stupid answer back. So to begin... How long do you think it takes to reach a 1000 posts in this topic again?