Rock Definition and 347 Threads

With recent abundance of security and cellphone cameras a lot of interesting and rare phenomena have been filmed. There are many videos of local landslides and rockfalls. Earthquakes commonly display shaking of buildings. Ground ruptures often happen in soft ground, in multiple places...

NASA people are excited about a new (old actually) rock that their rover Perseverance found a few days ago. Space.com article here. Short NASA video:

https://apnews.com/article/john-mayall-dead-3401a63d6aeb43f58ed48145ba82b7c3 https://www.washingtonpost.com/obituaries/2024/07/23/john-mayall-blues-dead/ https://www.rollingstone.com/music/music-news/john-mayall-blues-legend-dead-obituary-1235066448/...

To be underrated you have to 1) be really good 2) have had lots of exposure, playing on hit records and touring and such 3) nevertheless go unnoticed I've been making a fancy video with Blue Oyster Cult's Don't Fear The Reaper. Hearing it many times I gradually focused on drummer Albert...

He founded the band with Gregg and Duane Allman in 1969. One of my favorite tunes of theirs is the wonderful Blue Sky which he wrote for his girl friend at the time.

(i) A bulk density test gave an approximate value of 4.5kg/m3. (ii) The rock is ferromagnetic. It measures 16cm x 14cm at widest points and weighs 4.5kg. The bulk density would appear to rule out either slag. (iii) It would appear to have a fusion crack which stretches across one face and...

The voice of rock on UK radio along with John Peel and Tommy Vance. First female DJ on the BBC in 1970 and hosted the Old Grey Whistle Test.

You already know about Crossroads and Red House, so skip those. Etsushi Ogawa [ 小川悦司 ] I like the way this builds so gradually. You also get to see Senri Kawaguchi wearing a Peter Pan collar. John McLaughlin -- Tokyo City Girl I dunno that anyone else will like this but it's my fave...

Thank you for adding me!

all i could accomplish was calculating the distance between P and the ceiling in a horizontal line(6)

For this problem, The answer is ##6.28 m/s##, however, I got ##-314 m/s## and I am not sure what I have done wrong. My working is, ##H'(t) = \lim_{t \rightarrow 1} \frac{H(t) - H(1)}{t - 1}## ##H'(t) = \lim_{t \rightarrow 1} \frac{-1.86t^2 + 10t -8.14}{t - 1}## ##H'(t) = \lim_{t \rightarrow 1}...

a) I can find the compressive strain on the aluminium column using the formula ##\sigma = E\epsilon## as we know ##\sigma = F/A##. The area of the column is ##A = \pi r^2 = 0.126m^2## and the force on the column is ##F = 300*(9.8)N = 2940N##. The stress therefore is ##\sigma =...

I understand how to measure specific gravity of a rock. One weighs the rock then tares a beaker of water and then suspends the rock on a string to observe the “weight” gain of displaced water. My brain however could never get how, without adding a drop more water or adding the mass of the rock...

For part(a) and (b), The solution is, Can someone please explain the solutions to (a) and (b) to me? I don't understand where they got 5.77 cm from. Many thanks!

Jeff Beck, the British guitar virtuoso who rose to prominence in the 1960s as a member of the Yardbirds and later embarked on an acclaimed and prolific solo career, died Jan. 10. He was 78. https://www.msn.com/en-us/entertainment/news/jeff-beck-virtuoso-rock-guitarist-dies-at-78/ar-AA16eqam...

I tried to write a trajectory equation of motion.$$x(t)=vcos\alpha t$$ $$y(t)=vsin\alpha t-\frac{1}{2}gt^{2}$$from these we get:$$y=xtan\alpha -\frac{x^{2}g(1+tan^{2}\alpha )}{2v^{2}}$$For this problem:$$h=xtan\alpha -\frac{x^{2}g(1+tan^{2}\alpha )}{2v^{2}}$$ $$2h=(x+r)tan\alpha...

Hi everyone I have solutions to this problem, but I am not sure if the premise behind them is correct. I think this is the reasoning behind the solution for question d. - Work out how far the elevator travels in the 7s before the rock is thrown, so 7x2.5 = 17.5 - Work out how far the...

Hello! My friend found a rock on a beach near Ancona, in central Italy, and now he's convinced it's a meteorite. I have some doubts, however: it looks too cracky and porous. I'm attaching a few pictures of the rock: could someone give me an opinion? Thank you very much for the kind attention...

Hi. I'm an amateur mason - I currently use drills and plugs to split granite boulders. I've used sledge hammers, chisels and levers. I've dropped rocks, used hydraulic presses and tended fires to crumble and split rock. It's hard work. It's long hour work. I'm wondering if there's not a better...

Sort of. https://www.dailymail.co.uk/sciencetech/article-10897341/NASAs-Mars-Perseverance-rover-pet-rock-thats-hitching-ride.html

I found a round smooth like rock with orange and black stripes and it's magnetic Reference: https://www.physicsforums.com/forums/earth-sciences.84/post-thread...i don't know how to post picture

<Moderator's note: Thread split off. You guys take your fight outside (the jokes thread) :wink:> A body language analysis gives an interesting breakdown of this. Not a moral judgement, just whether it was staged or not in his opinion.

https://bigthink.com/starts-with-a-bang/al-naslaa-rock/ Terse description with a lot of photos. Al-Naslaa wins my vote for the weirdest one.

Hey Everyone, I am working on making a simulation of a rock climber on a wall in 3D space. The end result is to help visualize the free body diagram of the climber and show how moving your limbs moves your center of mass and changes the forces on your hands and feet. I've been struggling to...

A good candidate for the sample retrieval mission. https://www.nasa.gov/feature/jpl/nasa-s-perseverance-mars-rover-makes-surprising-discoveries

I need help in figuring out what type of rock this is. I found it on a beach along the coast of Northern California.

A small fragment of rock found lying in a field in Gloucestershire in the UK may not have looked like much to the casual passerby ... I'm curious how this was found, if not by a "casual passerby". Did there happen to be a meteorite expert wandering in the Gloucestershire field?

I have often been surprised to find music videos from the late 60s and early 70s, of people and groups like David Bowie, and The Guess Who. This surprises me because the first music videos I remember came along with MTV in the 80s. And I have often heard it discussed that MTV rushed in a new era...

https://phys.org/news/2020-10-carbon-creation-astrophysics.html Back in 2016 - Recent results in nuclear astrophysics https://arxiv.org/abs/1605.07810 From the abstract -

https://www.asi.edu.au/wp-content/uploads/2016/10/Physics_ASOE2015solutions.pdf Q`12b) Unable to understand how they deduct the relation between Ffall and N via the angles. Unable to tell why this would act along the axle of the cam to the point of contact with the rod and be relatable to each...

I know the acceleration of the rock is equal to g, but why. If we neglect air resistance, what is actually making the rock fall? Wouldn't it be that g overcomes the acceleration of the y plane at some point so the rock starts coming down or in this case accelerate more by throwing below 0 degrees?

I just love space rocks :biggrin: The latest addition to my meteorite collection NAME (LOCALITY): Huckitta, Huckitta cattle station, NT, Australia FALL DATE: Unknown, found 1924 (TKW 2300kg) CLASS: Pallasite, PMG-an WEIGHT g: 220.1g METEORITICAL BULLETIN: Never published in the...

Summary explains it.

The age of the oldest rocks on Earth & Moon are about 4.5 Gy old. But doesn't the material that made the Earth come from the supernova that had occurred prior to the formation of the Solar System, and doesn't the radioactivity dating measure the age of the creation of that material in that...

Hello, Could I please get assistance with a rock identification. I came across this one in the southwest part of the U.S. While I see a lot of slag from old mines, this rock appears to be something different than slag. Besides, it was the only dark colored rock I came across that day. It also...

Hello, Thanks for providing a forum where people can share their education/passion and help others. Speaking of helping out, could I please get some feedback on this rock I came across in the southwestern part of the U.S.? I picked it up because it didn't match anything else in the area. It sat...

Is there an easy way to explain this to a 3 year old?

Firstly I apologise for the most basic of questions... I want to know the odds for the game Paper Rock Scissors. What are the odds of winning What are the odds of drawing Thanks in advance :)

I fly in a spaceship on a 2d plane (for simplicity sake) in zero G. I eject a rock 90 degrees right to my forward vector. What does the equation look like if I want the final vector of the rock? I know the final speed of the rock is 100. What variables need to be known about the ship and rock?

Homework Statement :[/B] One swings a rock at the end of a string. We wish for the string to remain taut and for the rock to travel in a circulat path, in a vertical plane. What mathematical condition must the centripetal acceleration of the rock satisfy for the string to remain taut when the...

Homework Statement a rock is dropped off a cliff and falls the first half of the distance to the ground in 2.0 seconds. Homework Equations How long will it take to fall the second half? The Attempt at a Solution i thought if i took the square root of two and then subtracted that from 1/2t...

Homework Statement A catapult launches a rock with an initial velocity of 50m/s at 35 degrees above the horizontal. The rock must clear 3.5m at 10m away in order to make it over a castle wall to get to the enemy. Do the knights succeed? By how much do they clear the wall or miss clearing the...

i designed a cone drill bit with right hand thread to give friction and grab inside to give pulling force. my question is can this type of cone drill bit drill hard rock formations like normal tricone drill bits with teeth or the cone drill bit will be weak to penetrate hard rock formations .

Homework Statement Homework Equations U = (1/2)kx^2 T = 2 * π * (m/k)^ (1/2) The Attempt at a Solution [/B] T = 2 * π * (m/k)^ (1/2) T ^ 2 = 4 * π^2 * (m/k) k = (4 * π^2 * m) / T^2 So I know the initial potential energy is: U = (1/2)kx^2 U = (1/2)x^2 * ((4 * π^2 * m) / T^2) However, I...

About possibly using peridotite to capture large amounts of CO2 out of the air. Nice pictures, very little chemistry. NY Times story here.

Hi, so I have a problem that I am working on and I think that I understand Archimedes principle but the density that I am calculating is just absurd. The problem is as follows: "A geologist finds that a moon rock whose mass is 9.28 kg has an apparent mass of 6.18 kg when submerged in water...

A bird is located at the (50, 8 ) m coordinate. A boy shot a rock at it using a slingshot with the elevation angle $$37^{\circ}$$. How much velocity is needed for the rock to be able to hit that bird? I substituted all known variables (including the gravity acceleration $$10m/s^2$$, with...

Homework Statement A truck is moving at constant velocity. A rock is dropped from a storage compartment located at the midpoint of the ceiling of the truck. Where does the rock land on the floor. 2. Homework Equations Ax=0 The Attempt at a Solution [/B] The given answer states that the...