energy is conserved, no slipping or air resistance or anything.
There is a pulley, on one side is a mass resting on the ground, and on the other side is a larger mass above the ground. If the larger mass is released, what is it's speed when it hits.
okay, here is what I have:
PgM =...
A 2 kg copper block, initially at 100°C, is brought in contact with a 2 kg plastic block, initially at 20°C. They are kept in contact long enough to reach the same equilibrium temperature. The specific heat of plastic is four times as much as the specific heat of copper.
Which block will go...
There was an interesting conversation at Distler's blog between the owner and fh. I thought really thought-provoking points were raised.
I would like to copy some sample exerpts here.
the main address for Prof Distler's blog is:
http://golem.ph.utexas.edu/~distler/blog/
This particular thread...
Kids are hilarious, especially when they are eager to offer advice to complete strangers. This conversation took place in a Laundromat yesterday between a six-year-old girl and myself.
Me: (pulling old sweater from the dryer, noticing the thread pills that have formed)
Girl: If you have...
Max Tegmark, Lee Smolin--polite conversation at Peter's
interesting exchanges at Woit's blog
http://www.math.columbia.edu/~woit/wordpress/?p=310#comments
raising an important issue with the recent Tegmark et al, and Wilczek, papers.
links to those papers are here...
http://globetrotter.berkeley.edu/people4/Ekman/ekman-con0.html
A nice, wide-ranging interview with psychologist Paul Ekman, who's done ground breaking research on facial expressions and emotions. The interview was conducted on camera and you can watch it from the website (~1 hour), or you can...
ok, so not that GD needs another thread or anything... but, i really have no idea what to do with this. some guy imed me today, and i have NO idea what he said. i think he said he was speaking in a swiss dialect of german... but i could be wrong. other than that i basically understood nothing...
Firstly, I'm new here. I looked around a bit to see if there was another thread about String Theory. Didn't see any so I said what the hey. I certainly hope that this subject hasn't been beatin to death.
I'm not a physicist, nor am I overly educated. But I like to think that I understand...
This is a conversation a friend and I had; I'm not going to say who is me and who's the friend, so as not to bias anyone, but could some of y'all do me a favor and tell me exactly who you think is acting crazy in this conversation? This is bit of conversation is totally unedited and uncut, so...
I'm looking for suggestions on how to cope/deal with a social issue. I have a problem dealing with my friends. They are not the nerdiest people in the world, but they aren't dumb either. They achieve marks of around 80-89% for the most part.
However, they don't seem to have any interest in...
Detecting a secret telephone conversation?
Some people think that we can detect a secret phone conversation by separating the wires that come out of the telephone and by placing a pair of headphones along one of the telephone wires (see the figure attached, the wires are isolated). Will such a...
some people at PF like to talk about race: either to attack and belittle the notion, and deplore others using the word, or contrariwise to defend it. So a lot of information is flying around and you can learn a lot from the conversation. I've learned things I didnt know
somebody, Moonbear...
Hello all,
Just found the forum..
Wanted to say hello and that i hope to find stimulating debate and little flaming here:smile:
You will find me in the Physics and Tech section mostly.