Thanks Definition and 224 Threads

I have no idea how to go about this. Any help would be appreciated thanks :) Edit: I converted the 1.5 rev/s to rad/s = 9.4 rad/s

I'm feeling the need to thank the members of this forum for being so helpful and knowledgeable and for the admins and moderators who keep everything on track and relevant, it's an amazing learning resource. I recently joined a number of Space Science related Facebook groups and they are a total...

Hello. Be v grateful any assistance with this. Question is energy to haul 2000kg 4 metres up a 1 in 100 incline with 300 Newtons friction Answer is given as exactly 1.98 kJ. The only figures I can see that relate to anything here are 2000kg minus 10 = 1980, and 1:100 is 0.01 which times...

Any idea how much this would cost and how difficult? Should I forget about trying it myself and visit a university? Thanks

It's only a small PF shout out for my third novel, Handwavium, because it is more techno thriller than pure sci-fi story, so it didn't ask much from the collective brainpower of the forums. Still @Vanadium 50 and @stefan r gave their assists with gravitational wave triangulation, for which I...

At what value of α is the curve y=asin2π/λ (x+α) in phase with z=asin2π/λ(x)? My answer booklet says α=1−λx+nλ, but I keep getting α=nλ, where n=0,1,2... I have no clue how to get to the answer shown in the mark scheme. Any insight would be much appreciated!

I haven't been on PF that long, and I mostly post in the Science Fiction section, but I have noticed in the "Writing and World Building" forum that few of us loop back after asking for help to let people know, "My novel is done". So, just to let you know, my novel is done and is live in the...

https://www.nature.com/articles/d41586-020-00965-x?utm_source=twt_nnc&utm_medium=social&utm_campaign=naturenews&sf232171849=1 Cheers, Tom

Homework Statement It requires 10 microliters of a Cu(NO_3)_2 solution to produce a spot of 1cm in diameter. If the Cu(NO_3)_2 solution contains about 6g Cu^2+ per liter, then how many micrograms of Cu^2+ ions are there in one spot? Homework Equations simple dimensional analysis problem: 1st...

Hi I'm Robbie, a uni student studying physics and mathematics. I hate experiments and I like theory. Also, I'm not passionate about physics, yet. I really enjoy investigating math maybe because it has a much lower barrier for discovery (and breadth) in comparison to physics. Anyways, I hope I...

$$\int {z}^{2}\arcsin\left({\frac{a+\sqrt{392-{a}^{2}-2{z}^{2}}}{2 \sqrt{196-{z}^{2}}}}\right) dz$$ $$\int {z}^{2}\arcsin\left({\frac{a}{\sqrt{196-{z}^{2}}}}\right) dz$$

Homework Statement 1. Homework Statement [/B] https://ibb.co/b263Pw Homework Equations [/B] Use thevenin method to find the intensity between A and B The Attempt at a Solution Well I tried a easier method but I just can't find the same answer[/B]

Hi there: I am looking for approximate expressions for the two functions: ln(x) and 1/ln(x) . Any help? Thanks in advance.

About to start reviewing for a math test but it has been ages since I was in school. Hoping some of you math savants could help me out. Will hope to understand and be able to complete these two exams. Starting with the first one below. (Do you guys know of a better exam to test and know...

Homework Statement The box's measurements are 277*120*195mm. The lamp's power is 15W. Trying to figure out how long it will take to heat the box so that it reaches a given temperature. According to Wikipedia ρair=1,2kg/m3 and cp air=1004J*K-1*kg-1 Homework Equations ΔU=m*cp*ΔTemperature E=p*Δt...

John lives in Dallas and his kitchen has a room temperature of about 70 degrees fahrenheit. He wanted to make her family some cookies for dessert, so he preheated her oven to 350 degrees fahrenheit. In 1 minute, the oven was 135 degrees fahrenheit. In 2 minutes, the oven was about 200 degrees...

I'm a mechanical engineering from Universidad Tecnologica de Bolivar(Cartagena Colombia) . Right know studying Computational mechanic material(more specific: Isogeometric analysis). I'm really newbie in this and hope than some on your can help me because is just the beginning of something more...

Homework Statement A cylinder of mass m and radius R is set on a plane, with large enough friction coefficient to ensure at any moment rolling without slipping. A constant torque is applied along the axis passing through the center of mass (G) of the cylinder and perpendicular to the basis of...

Homework Statement Refer to the diagram. Homework Equations Refer to the diagram. The Attempt at a Solution Stuck from the beginning.

Homework Statement a small lump of ice at 0 degrees celsius falls to the Earth's surface. when the hailstone hist the surface, all of the kinetic energy of the hailsotne is transferred to thermal energy in the ice. calculate the minimum speed of the hailstone so that it just melts when it hits...

Sometimes the enemy of your enemy is still an enemy, but also a friend... Pregnant women are more susceptible to malaria, scientists were able to link this to a specific sugar in the placenta that seems to be relevant for its rapid growth. The same sugar molecule is found in most types of...

I transferred into my school's physics program with all my core curriculum done, so I only have to take physics and math courses to finish my degree at this point. The physics program at my school is pretty small so pretty much all courses are only offered in either the fall or spring, and there...

Hello!:angel: I am 9th grade and this year I want to participate at different physics olympiads and show result , I am training already but I need some more advices from people who have more experience , can you give me the list of books ,sources and suggestion with which you started to study...

I actually registered primarily to thank another user (lordloss). My TI-89 Titanium wasn't responding to anything. Putting in batteries turned it on, but then it'd be locked up. I tried all the tips and tricks (key combinations, etc.), but it wasn't recognized by Windows to send new firmware and...

Thanks all for your contribution to PF! I am from University of Macau (UM) and am very glad to be a member of you! Best regards! Wangjade 22/05/2015

I just signed up in physics forum. am an electrical engineering student looking foward to a amazing learning experince at Physics Forum. Thanks!

Just panicking before exams, thanks to everyone who can clear things up for me across the sciences. You are doing a great service. Immense thanks again, enjoy your weekends!

1. Homework Statement If the optical path diff between two light waves is lambda/2 will they always interfere destructively? if this in true then wherever one wave undergoes aphase change of pi at one surface and the second wave does not then these two will always interfere destructively...

Could someone please explain this question to me I'll include what I thought the answer was and the actual SQA answers. Please can you read my answer just to see what I'm doing wrong and what I don't understand It's from the 2009 past paper AH physics Thanks so much I really appreciate any...

Hi everyone, Is there a simple formula/equation for calculating the mass of a star simply by measuring it's redshift. I know there is a way to do it, but have been unable to find any clues on the web.. Thanks for your help! :)

Hi guys! I am having a problem in finding the inverse z transform of the given signal. Can anyone help me? I'd appreciate it. Thanks! Here is basically what I did: However, I don't know what to do next. What is the next thing to do? Thanks!

I've loved science for a long time. In fact it was one of my favorite subjects in school and was inspired to go for marine biology in collage. Admittedly I didn't cut it and left that path. I still look to educate myself and experiment. I'm writing papers to define myself and what I want in...

Since nobody else seems to have mentioned anything about it, I want to thank the teams and fans at Wednesday's Flyers/Penguins hockey game for singing our national anthem in support of Canada after our terrorist murder and House of Commons shoot-out. As far as I know, that's never before been...

If I travel at the speed of light and have a mirror can i see my reflection? Thanks Any ideas?

How to change the upper step to lower step on the figure? Why does N2(0) change to N2(t) the exp(-t/21) will be missed? Thanks.

THANKS ALOT!

Today I made my 1,000th https://driven2services.com/staging/mh/index.php?posts/55191/. Here is to many more to come! I want to thank the staff for making this forum such a pleasant place to be.

\int_{0}^{a}\frac{x}{(x^2+z^2)^\frac{3}{2}}dx Hi all, I'm stuck on this one. Sure there's an easier way to do it. Don't have my calc book currently. Thanks!

Hi, I've been trying a couple of proofs that my calc teacher gave me, but I'm not sure if I have the right approach or not. 1) Prove that the degree of the depressed polynomial is exactly one less than the degree of the original polynomial. - For this proof, all I can come up is the face...

A fence is to be on posts 8 meters apart around a rectangular lot that measures 40 meters long and 16 meters wide. How many posts are needed, including the ones placed at each corner, to fence the entire lot?

Cool. Now Evo is only 5 times as active as me :smile:

Anyone know what is the major weakness of a Buck Regulator that compared with a Linear Regulator? Thanks.

A firecracker with mass 100g is propelled vertically with a launch force of 1.2N applied over 5s, after which it explodes into two 50g fragments. One fragment goes horizontally at 15m/s and the other goes to the right at angle 53 degrees with the horizontal at speed 25 m/s. find the distance...

Hardest physics question/task. No naysayers please! :) Thanks Here's The Challange: I realize that this may be better suited to be posted on a magic/illusion type forum, but without implementing gimmicks and gadgets to perform this is more a task/question for physicists than...

1. Homework Statement A train has a mass of 5.77E+6 kg and is moving at 99.4 km/hr. The engineer applies the brakes, which results in a net backward force of 1.11E+6 N on the train. The brakes are held on for 26.9 s. What is the new speed of the train? How far does it travel during this...

Hello everyone, I know electronics pretty well. I'm pretty good with that, but my physics and chemistry understanding of what is going on is a little weak. I'm trying to do a good Youtube video on Ohm's law and I want to have a solid foundation to my understanding. Not just V = IR, but...

Homework Statement 1)Wally whacko claims to have invented a heat engine that will revulutionalise the industry. It runs between a hot source at 300 C and a cold sink at 25 C . he claims that his engine is 92 % effieicnt. What is the max efficiency of his engine ? in 2sf (2)At a certain...

...Chris L T521 and Jameson for their hard work and diligence regarding the POTW. You guys are like clockwork with the problems, and also manage to find very interesting problems. I think I can speak for everyone when I say it is greatly appreciated!(Yes)

Dear Physics Forums, On behalf of all the non-educated, wikipedia surfing, can't-do-the-math members and non-members of the forums, I would like to say Happy New Year! 2012 was an awesome year here on PF, and we reached new milestones in posts, threads, and most users online several different...

A hockey player sends a .4kg puck at 80 m/s. A stationary golie cathces the puck. If the coefficient of friction of the golie on the ice is .05 and his mass is 90 kg how far does he slide on the ice before he comes to a stop. I have found normal force = mg = 885.92N and then friction =...