# Science Help

25840 Posts - Page 1 of 1292

## Same- marriage legal across US

Yay :) The United States becomes the 21st country to legalise same marriage across the entire nation http://edition.cnn.com/2015/06/26/politics/supreme-court-same--marriage-ruling/index.html

## Newton's 2nd law question

If a constant force is applied to an object and the force is pushing the object up a inclined ramp with constant velocity what is the acceleration if mass is unknown? F=ma F=m (1m/s^2)​If i apply this equation then acceleration is 1m/s^2. Am i applying this formula correctly?... Newton's 2nd law question

## Can't Connect to Netburner PK70

Hey guys, I am working with a couple Netburner PK70 controllers and can only access one of them via Ethernet, but the other one (which has been formatted by the previous person on this project) Can't seem to be accessed by any of the Netburner software, I am currently running Advanced IP... Can't Connect to Netburner PK70

## Problem in Geometric Probability

The normal algebric probability is easy to understand but I find the geometric probabilities less understandable. Can you please help me with a few problem related to this area of probability so that I can understand it better. Here are my problems, 1. Two persons A and B agree to meet at a... Problem in Geometric Probability

## MatLab pdepe

Hi PF! I am trying to solve a pde in matlab and started by using the generic code mathwork supplies and then augmenting for my purpose. After defining the function below and run the script, i can do anything to the ##f## and nothing changes. I can literally delete the line and still I receive... MatLab pdepe

## Check my work on these proofs? (basic set theory)

1. The problem statement, all variables and given/known data I am going through Apostol's Calculus volume 1 and am working through I 2.5 #3. I'm not very familiar with doing proofs so I just wanted to make sure that I got the right idea here. Here's the question: Let A = {1}, B =... Check my work on these proofs? (basic set theory)

## Hamiltonian for spherically symmetric potential

1. The problem statement, all variables and given/known data A particle of mass m moves in a "central potential" , V(r), where r denotes the radial displacement of the particle from a fixed origin. From Hamilton´s equations, obtain a "one-dimensional" equation for $${\dot p_r}$$,... Hamiltonian for spherically symmetric potential

## Photons and energy

Hi people. I'm currently well into my 4th novel, 'The Atlas of Elegance.' it's a book about magic - but a kind of magic based around physics, in particular quantum and astrophysics. The main characters in the story have the ability to control matter at a sub-atomic and quantum level. I'm using... Photons and energy

We will now be publicly announcing newly awarded members for inclusion into the Science, Homework and Education Advisor programs. To kick this off I will announce the first class of the new Education Advisor program. @Choppy @Andy Resnick... New Advisor Announcements

## Reflected wave from free end

A wave pulse on a string moving from left to right towards a free end will reflect and propagates from right to left with the same speed and amplitude as the incident wave, and with the same polarity. My question is, why the slope and the vertical force must be zero at the free end? If the... Reflected wave from free end

## Newtons 2nd law question.

If a constant force is applied to an object and the force is pushing the object up a inclined ramp with constant velocity what is the acceleration if mass is unknown? F=ma F=m (1m/s^2)​If i apply this equation then acceleration is 1m/s^2. Am i applying this formula correctly?... Newtons 2nd law question.

## An observation about relativistic space travel...

I suppose I am not the first to notice this, but if you are going at say, 0.999c you will have shrunk by a factor of about 20 and everything else on the craft. Suppose the spacecraft is 2000 meters long, at 0.999c it will shrink to about 100 meters long. So suppose a person 2 meters tall, 2000... An observation about relativistic space travel...

## Moon Earth binar system by math

Hello, I'm interesting in Earth Moon evolution history. I understand it is very complex problem, and I can find many articles about that. But I would like to start from beginning and add real condition on my model step by step (I hope good way to do something). I would like to start with... Moon Earth binar system by math

## increase temperature of liquid in a box without heat convection or conduction

hello I have a liquid or gas inside a metallic box (eg. stainless steel 5mm thick) how can I increase its temperature without heat convection or conduction?

## Wolfram Mathematica: ListPlot3D to SphericalPlot3D

Hello! There is a problem with Mathematica: i calculate an integral with a help of NIntegrate and get the whole list of spherical coordinates, like {6.24, 3.14, 0.323488}, {6.26, 3.14, 0.323488}, {6.28, 3.14, 0.323488} and so on... then i create a list, like data = List[{6.24, 3.14, 0.323488},... Wolfram Mathematica: ListPlot3D to SphericalPlot3D

## Popular misconception -- When the deuterium nuclei fuses to form a helium nucleus

I am no Einstein but I would like to expand my knowledge and share it. When two deuterium atoms fuse together they become a helium nuclei. Now deuterium nuclei contains 1 proton and 1 neutron. When the deuterium nuclei fuses to form a helium nuclei. Helium nuclei contains 2 protons, and 2... Popular misconception -- When the deuterium nuclei fuses to form a helium nucleus

hello all, I am in the process of measuring coefficients of a rectangular panel using given table in textbooks to obtain them. I have attached a simple figure of two situations; left is my current situation to analyze- a clamped end and compressive force on the other end. The situations... Question on intrepretation of loading

## Impulse Force on support?

Hi, i have a question.. I need to make a "bumper project" as shown in figure. I have all the geometric information about system and also know weight and energy which is transferred. I need to calculate the support reaction but i can not convert the energy to the force without "impact time". (F... Impulse Force on support?

## atomic electromagnetic simulator

hello is there a software that simulates electromagnetic field around atoms, materials? to simulate the forces that drive chemical reactions? thanks!

## Popular misconception.

I am no Einstein but I would like to expand my knowledge and share it. When two deuterium atoms fuse together they become a helium nuclei. Now deuterium nuclei contains 1 proton and 1 neutron. When the deuterium nuclei fuses to form a helium nuclei. Helium nuclei contains 2 protons, and 2... Popular misconception.