Rock Definition and 351 Threads

A 52 kg rock climber is climbing a “chimney” between two rock slabs. The coefficient of static friction between her shoes and the rock is 1.33; between her back and the rock it is 0.89. She has reduced her push against the rock until her back and her shoes are on the verge of slipping. (a) What...

I rather liked https://www.physicsforums.com/showthread.php?t=110807", and thought it had potential (for imagination that is - HINT HINT :rolleyes:), but it was shut down when it became too silly. With Evo's permission (granted), and Mattara's permission (pending), I'd like to start it again...

Hi Everyone! I've been working on this Physics problem for the last week and I still can not figure it out! I'm sure I'm missing some very basic concept, but I'm not sure how to proceed: An Australian bushman hunts kangaroos with the following weapon - a heavy rock is tied to one end of a...

Another forum game: Here's how it works: The Rules: 1 - No posting something that can't be beaten (God is the traditional example of an unbeatable object; however, Parallel Universes is a much better example, since it could be argued that atheism or Buddhism beats God...) 2 - The...

Just curious if this was the right way to do this problem. A tire is going at 180 rev/min. There is a rock in the tire (on the outside) and the tire has a radius of .5 meters. What is the speed and acceleration of the rock? 180 rev/min = 3 rev / s 3 rev/s means its going 3...

Hope these questions will rock you too to give me some answers! why does the Earth's inside get cooler but its surface get hotter ? (hot because radiation/heat from the sun) and the polar caps are getting melt as reported due to green house effects etc, which doesn't seem logical to me...I...

This is the second hardest question on my test, how long does it take to push a rock 10m. 50Kg rock 10 m is the distance 0.16m/s2 is the acceleration Does anyone know which kinematics equation I should use for this problem.

I have this one problem solving question that confuses me. Someone pushes a 50kg rock a distance of 10m in a recent competition of strength. The coefficient of friction between the rock and the ground is 0.8 and the person exerts a force of 400 N. I've got my free body digram with my applied...

A 7.94 kg stone is resting on a spring. The spring is compressed 10.2 cm by the stone. (a) Calculate the force constant of the spring. (b) The stone is pushed down an additional 28.6 cm and released. How much potential energy is stored in the spring just before the stone is released? (c)...

a rock whirls in a vertical circle of radius 8m. acceleration of gravity 9.8m/s^2 what must the speed be to have tangential=radial acceleration when the string makes a 37 angle with respect to the vertical? is it Wsinangel=ma v=Wsinangle*r/m)^1/2 ?

http://www.guardian.co.uk/science/story/0,3605,1652178,00.html ---quote from Guardian--- Probe returning to Earth after asteroid landing Alok Jha Monday November 28, 2005 The Guardian The Japanese space probe Hayabusa began its journey home yesterday after becoming the first...

I need some advice. About a year ago I found out that my girlfriend had cheated on me. Two weeks ago we broke up, and I won't go into details suffice to say that we are still friends. Now a close friend of mine is having a party to celebrate his 21st this weekend and both my ex and the guy she...

Again another work/kinetic energy problem I need help with. A small rock with a mass of 0.240 kg is released from rest at point A, which is at the top edge of a large, hemispherical bowl with a radius R = 0.500 m. Assume that the size of the rock is small compared to the radius of the bowl, so...

The standard way to measure porosity of a rock is to get the pores completely saturated with water, then weigh the rock immersed in water and again in air (there are modified balances for this). Using Archimedes' principle, you then can determine the volume of the rock. Then you dry the rock...

I'm not sure if this question will make sense, but is there a difference between a rock and a stone and if so, please explain. I'm also curious as to when a rock can be called a stone, or vica versa. Thanks. :bugeye:

I have a pretty extensive collection of rare punk rock cds that I cannot afford to replace as the cds get old and scratched- who knew physics would pay less than punk rock- I truly didn't think it possible. Anyways, does anyone have any experience with trying the cd resurfacers that are found...

Here's the problem: A soccer player kicks a rock horizontally of a 40m high cliff into a pool of water. If the player hears the sound of the splash 3.08 s later, what was the initial speed given to the rock? Assume the speed of sound in air to be 343 m/s. ** my question is, what role does...

Many people already know the answer to this, but pretend you don't, and if you have never known the answer consider yourself lucky it's a good puzzle. How does a stone form, I mean how does it by simple degrees and pressure and time go from a lump of mud to a hard conglomerate of rock or solid...

Hey... need some help with this quesiton: A rock is dropped from a sea cliff and the sound of it striking the ocean is heard 3.2 seconds later. Ifthe speed of sound is 340 m/s, how high is the cliff? multiplying 3.2 by 340 gets me 1088 m which doesn't seem right. How do I go about...

They haven't figured out what is causing these anomalous hot spots near Santa Barbara: Earthfiles.com Address:http://www.earthfiles.com/news/news.cfm?ID=938&category=Environment

as shown: in the picture, look at figure d) (attachment) don't worry about figure a) --- given: 720 gm rock each string has a tension of 29 N the rock is held by two of the 45 cm strings with ends 56 cm apart and whirled in a circle between them. Neglect gravity. What is the...

Q: Your starship, the Aimless Wanderer, lands on the mysterious planet Mongo. As chief scientist-engineer, you make the following measurements: a 2.50-kg stone thrown upward from the ground at 15.0 m/s returns to the ground in 7.00 s; the circumference of Mongo at the equator is 1×10^5 km; and...

Who are the greatest hard rockers of all time? A few of my favorites volcalists are: Steven Tyler - Aerosmith Freddy Mercury - Queen Mick Jagger, of course. I think these guys pretty much set the standard.

Rock the Suggestion Box Like the Feedback Forum, but hipper ! :biggrin: No need to wear well-brushed suits and shiny leather shoes here. No need to bow to the Uberlords as you enter. Heck, we don't even care if you don't iron your underwear before wearing them ! :wink: Just drop your...

http://geomaps.wr.usgs.gov/parks/deva/racetrack.pdf [link updated] 6/20/09 New Paper Claims Explanation https://www.physicsforums.com/showthread.php?t=60676&page=5#90

I just started physics about a week ago. We got this problem for extra credit, and I need help with it. A rock is dropped off of a cliff and the sound of splashing water is heard 3.4 seconds later. The speed of sound is 340 m/s. How high is the cliff? Any insight/help you could give me...

As I type this, I listen to “The Zephyr Song” by Red Hot Chili Peppers, and I have just begun to contemplate odd ideas. I don’t understand why I feel some sort of awkward attraction for the life of rock stars -- especially eccentric, intelligent, and such wild ones. I am a practicing Christian...

A crewman on the starship Enterprise is on shore leave on a distant planet. He drops a rock from the top of a cliff and observes that it takes 3.00 s to reach the bottom. He now throws another rock vertically upwards so that it reaches a height of 2.00 m before dropping down the cliff face. The...

I understand that this is a bit cheeky but I've found a problem on one of my mechanics problem sheets that is giving me a headache. As much as I could just ignore it I'd rather try and gain some more understanding of the vague world of rotation and orbit Even at this early stage I'm...

Q A 420 gm rock is whirled on the end of a string 44 cm long which will break under a tension of 21 N. a) What is the highest speed the rock can reach before the string breaks? (Neglect gravity.) For this I used F = mv2/r and calculated velocity in m/s which is correct. b) If two...

physics help! :confused: Ok, I have understood every problem we have done so far except this one, You are wearing shoes that have a coefficient of friction on rock of 0.70. On how steep a rock slope could you stand without slipping? So far i have gotten: Fs=Fparallel= mu*W*costheta...

A 0.26 kg rock is thrown vertically upward from the top of a cliff that is 30 m high. When it hits the ground at the base of the cliff the rock has a speed of 25 m/s. (a) Assuming that air resistance can be ignored, find the initial speed of the rock. (b) Find the greatest height of the...

Sometimes I go to Disco, the music is very Hot! :smile: But I don not know its title and singer. Please give me ten songs with their titles and name of artists, so that I can look for them.

hey, pls smne take a look at this question, i need help. " A man stands on a cliff 15m above the ground and throws a little rock off the cliff with a velocity of 30m/s at an angle of 33.0degrees. Air resistance can b neglected. what is the speed of the rock just before it hits the ground?"...

rock is dropped from cliff. it is heard hitting the ocean 3.00s later, if speed of sound is 340m/s, how high is the cliff? im so stuck

A man stands on the roof of a building of height 16.3m and throws a rock with a velocity of magnitude 31.6m/s at an angle of 28.1 degrees above the horizontal. You can ignore air resistance A.) Calculate the maximum height above the roof reached by the rock. Take free fall acceleration to...

Struck in head by rock! This past Sunday I was rock climbing in Eldorado Canyon, Colorado. Another climber was on a route just left of me and well above me. When he climbed up onto the belay ledge he accidentally knocked loose several rocks. One rock hit me in the head. Fortunately, I was...

I personally think Led Zeppelin's "Stairway to Heaven" is the best rock song ever. No matter how many times I hear it, it never gets old. Whatdaya think?

I am looking for an explanation on how bar magnets or lodestone works. After searching the internet I found many articles on magnetic fields, electricity causing magnetic fields, electromagnets, etc. But I wasn’t able to find an explanation on why lodestone naturally attracts other metals...

My name is Steve LeMaster, Professor Robert M. Schoch's webmaster and moderator. I am not quite sure if I am posting my query in the right place, so please forgive me if I am. Dr. Schoch is a geologist at Boston University and he has told me that geologists do not know at what rate rock...

Ok, I missed last class period, but I have the general idea of this I think. I just don't know how to put it all together for this one... A rock that weighs 40 N is dropped from a cliff 20 m above the ground. What is the kinetic energy of the rock when it gets to the ground? (disregard air...

Me and a couple of my classmates are trying to convince our physics teacher to do an "excursion" to a local rock gym for a day. He said only if we could come up with a GOOD HARD problems based on the physics of the climbing and the belaying. Now, i have a basic understanding of physics and it...

A rock is thrown at 25 m/s in a 50 degree angle (horizontal). At what time will the speed reach an angle of + / - 30 degree (horizontal) ?? answer is 1.01s and 2.91s thx u

Swinging Vine(HELP ASAP) All help is apprieciated. Backwoods Allister hunts deer with the following weapon...a rock attached to a 2m vine. He holds the end above his head at a point 2m above the ground, when the above ground angle reaches 60 degrees with the vertical the rock breaks off and...

Ok i don't want this to end up a royal rumble between people who disagree with each other, cos i know u guys (n gals) are much more civil than that. Anyway, in an effort to boost my cd collection and my views on newer bands, i would appreciate it very much if u guys could tell me your...

Picture is attached as follows: A 480 gm rock is whirled on the end of a string 47 cm long which will break under a tension of 27 N. a) What is the highest speed the rock can reach before the string breaks? (Neglect gravity.) b) If two other strings identical to the first were attached...

If a rock is dropped off of a sea cliff, and the sound of the rock hitting the water is heard 3.4 seconds later, how tall is the cliff, assuming the speed of sound is 340 m/s. What I've been trying to do is break the problem up into 2 parts, one for the rock going down towards the sea, and one...

If a rock is dropped off a sea cliff, and the sound of it striking the water is heard 3.4 seconds later, how high is the cliff, assuming the speed of sound to be 340 m/s. I don't really know where to begin with this one, and I would really appreciate the help. Thanks.

"The ancient dates for the paintings cast little light on the mystery of who made them and why, but it suggests that whoever the painters were they came well before the Aztecs established their culture in central Mexico some 3,000 years ago."...

Looks like ol' Bush is going to be a bit uncomfortable when asked to comment on the 6-to-3 ruling in favor of gay @ss sex in the state of Texas (his homestate). If he makes a positive comment, he'll lose the favor of some of his own supporters. If he makes a negative comment, he'll be hated...