Classical Physics

As I understand it, escape velocity refers to the speed necessary for an object to escape the gravity of a body. Could the speed be lower if the object takes a less direct (<90-degree) trajectory, such as a plane uses? If so, then does escape velocity only apply to a vertical takeoff and trajectory? Thanks.

Dear all, I explored the value of PI up to 10 million digits with the following link http://pi.karmona.com/ From here I realized that it included many scientific constants. Below are some examples (See the string in BOLD) · 85236194426736533892035293381796879434588513096544808259521653348853314258590660527010020998130498690661069867723414515021618033218172517802616380355080061151485165018703481386496623229835504747481403 Where 1.618033 ~ golden ratio to be used in design, painting, and architecture etc. (Source: http://mathworld.wolfram.com) · 966851963914139974487568434347136834676844051916283024004113004444635439041050505510885029827…

If we take a gallon of mercury into space and squirt it out from a circular orifice, will it stay all together as a 'string'? All the ifs, ands, and buts entertained. Like... a string will form if the pressure is right, and the orifice is smooth, but not if too close to mass x.

Hello everyone, I thought about this problem just for a while and couldn't exactly figure out what would happen. I don't have the necessary equipment, so can't perform the experiment. Suppose a wire attached to a metallic ball hangs, such that it is free to move to and fro [see figure]. A conducting base is provided below the ball, such that the surface of the base just touches the ball, providing negligible friction. There are two concave magnets providing a uniform magnetic field to the ball. The ball and the wire and the base all are connected to a circuit with AC supply. So, as soon as the key is pressed, the current flows. Accordingly, a force will cause th…

If there exist materials with infinitely low dielectric strength (superconductors), can there be a "superdielectrics" with opposite effect? Materials with infinite dielectric permittivity and reasonable dielectric strength in the same time? Or it's proved that such thing is theoretically impossible?

does anybody have an answer to why this is happening in this video ? youtube link removed by moderator The common acronym for DeoxyriboNucleic Acid, an essential component of our genes, is...

Ok, here is an example of a Tyre Curve: This is totally missing a dimension: speed. If a car is going 1 mile per hour...shouldn't it have 100% grip and no slip at all times? Similarly, if a car is going 200 mph sideways, shouldn't it have much less grip than the diagram implies? So I'm basically unsure how to approach this in terms of using this for realistic car physics.

here is the link to walter lewin video lecture please jump to 13:13 8.01x - Lect 2 - 1D Kinematics - Speed, Velocity, Acceleration i thought that all meter ruler/ meter stick use ± 0.1 cm as uncertainty .how did he get ± 0.5 cm?

Guys can anyone see where I'm getting these negative values from. Probably need to sleep tbh. I know it's probably that -36 but I can't think why, it shouldn't be so... Any ideas would be great.

Hello all, I'm Dan and am just somebody with an interest in general science. I've a 'Pop science' level of understanding you might say. I occasionally pop over to your Forum and read through some interesting threads, the level of knowledge usually quickly surpasses my own, but each time I gain a little more myself. So, my question. I often like to have a little ponder on one very specific topic and try and follow some train of thought to some sort of a conclusion. Sometimes I think I have a good conclusion, sometimes not. Gaps (chasms) in my knowledge prevent me from finding the answer to the question, "Light does not accelerate or decelerate, what fundamen…

Apologies for the size of this image. I did try to resize it on Photobucket. Seems to have had little effect. So I'm having a problem with this. I've been studying the past several hours, learning how to calculate these things. The more simple type. eg. Find ib, ie, ic, Vcb, Vce... I had taken notes in class, for the answers to this new type of question above; where we have this VCE(sat) thingee... Now I've written:- IC = (VCC - VCE) / RC IC = 5.02 / 6000 = 0.8mA Question is where the heck am I getting this 5.02? At first I thought I'd gotten the 0.2v from the VCE(sat) thing wrong. That it should have been 0.2 instead of 0.02 and that I sho…

What can efficiently suppress electron-hole recombination in some materials? Let say we want to create a conductor with good electron and hole conductivity simultaneously. If we will dope semiconductor with an equal amounts of acceptor and donor admixtures, they will simply recombine and bring conductivity to a low level. Are there some exotic materials or materials with an exotic band structure where electron-hole recombination would be completely suppressed? For example, what about materials with inverted band structure similar to HgTe? Also, can hole and electron recombine if the hole have higher energy than the electron? In which cases recombination in some materia…

Hello everyone, I have been doing some research about Helmholtz resonance of a bottle for a science competition, but I don't find it clear how the Helmholtz frequency in a bottle is connected with a concept of seeing a bottle as a closed tube of a length L and fundamental frequency f=v/4L ? I understand that the latter formula does not consider the shape of the bottle, while Helmholtz resonance does. When we pour liquid in the bottle and observe the change in resonant Helmholtz frequency with change in volume, we see that shape matters (I guess because if affects the amount of volume of air in the "resonator"). Still, if the bottle looked like an almost perfect cylinder a…

Hello, is it possible to create a magnetic web? By a web I mean like a magnetic field that's equal throughout a whole shape, and the shape is surrounded by something? Like for example, imagine having 5 pillars: - - - - - And inside all those pillars having a magnetic field that is only inside that field. Is this possible?

Hi guys I'm new to the forum. I hope this is in the correct area of the forum. Struggling with a few problems on capacitance. Here's the question. Determine CT for the circuit below. So I'm thinking this is the equivalent capacitance. Now those three capacitors in uF. I'm thinking they should all be in parallel in which case they get added. I think... Then the CT for them should be 0.111uF 10000pF I've worked out as 0.01uF So 0.111 in series with 0.01... looks like to me...? [math]1/((1/0.01)+(1/0.111)) = 9.17*10^{-3}[/math] Problem is I have 0.121uF as the answer from the lecturer.

Suppose that there's a body of mass m moving with uniform velocity of v in the horizontal direction of XX' ( see diagram). There are two massive bodies m1 and m2 which lie at a distance of r from centre O. So, as the body moves, the two bodies will influence its course of motion due to gravity. My question is how the motion of the body will be affected? From analysis, I found that if m1=m2, there will be a net force in the XX' direction, causing the body to accelerate upto O. At O, it's velocity is maximum. But, as soon as the body crosses O, there will be a net negative force, causing it to decelerate. If the velocity of the body at O is below the escape velocity, then…

So, I was tutoring a student and we got to a question of a type I've seen before. A block attached to a spring is resting on a frictionless horizontal surface. A bullet is fired into it. You're told the amplitude of the oscillation and the spring constant. So, you find the total energy. You get the right answer. Another part of this question is to find the speed of the bullet before it hit the block. So, you set 1/2 mv^2 equal to the total energy found above, and solve for v. But somehow, I kept getting the wrong answer, and this was very embarrassing in front of my student. Is there a trick here?

If a rocket launches from earth, and lets say that it moves up 5m in the first second, then it will do work of force times distance - let's call the amount w. If we wait until it reaches a velocity of 100m/s, then we can calculate the work being done over that particular one second as 20w but the energy expenditure is the same. How is this possible ?

I wonder if your room becomes isolated from any gas coming in or getting out, -you will of course consume all the Oxygen in the room to the last bit- my question is that how can we delay it, does opening closets, opening your water bottle or killing some of your own cells makes a difference? Should i boil drinking water to save myself?

If I we're to state that the perimeter of a circle is always equal to or less than its area? If the argument (equal to) only appears once would this take away from the accuracy of the statement?

If thou wouldst follow Newton in his Book 1, Section 3, Proposition XI and deduce the inverse square law from Kepler's observations of elliptical planetary orbits, first know thy Conics. In particular, the proof uses these properties of the ellipse : 1. The sum of the lines joining the foci to any point on the ellipse is constant 2. The lines joining the foci to a point on the ellipse make equal angles with the tangent there 3. The area of the parallelogram formed by the tangents at the ends of any diameter is constant 4 . The 'symptom' of the ellipse viz. for any diameter, the ratio of the square of an ordinate to the product of the abscissae is constant New…

I'm having the strangest problem with my kitchen sink ... one that seems to defy the laws of physics! My pipes are clogged. Normally, I can take the pipes apart by unscrewing them and simply scooping out the crud in the pipes with a spoon. But this time, the clog seems to be so far down that I can't reach it. I've tried liquid clog remover, but that doesn't work. But here's the weirdest part: If I put water in my sink, it will take about 10 minutes to go down the drain. That's slow, but at least it gets the job done. But when I took the pipes apart to attempt (in vein) to scoop out the crud, I noticed that the water in the bottom pipe (the only pipe I can't unscrew) ju…

Which methods are best in water molecules dissociation to obtain OH- and H+ ? Lasers, microwaves, electric current? Which methods are most energy efficient to obtain as much as possible ions at a time? Which frequency have to be used?

I was thinking about this, and couldn't think of the answer. Two objects far away from each other accelerate toward each other in space because gravity attracts them to each other. They come together to form one object. When the two objects were far apart, their combined energy was less than the newly formed object has. Where did that energy come from?

i have learned that gravity is caused by mass bending the space around it, how ever, this makes no sense at all to me and does not explain how the planets actually move. sure, it explains why planets move in orbits around a larger mass, but it does not explain how. there must be some type of force present that actually gives the planets their motion. it would be impossible for objects to just decide to move because the space around it is bent. i mean, space can be bent all it wants, but this alone can not induce motion on other objects, there has to be some force that pulls or pushes the planet in the first place, other wise, all planets are using magical powers to move …