Laws Definition and 1000 Threads

1. The distance between two telephone poles is 50.0 m. When a 1.00-kg bird lands on the telephone wire midway between the poles, the wire sags 0.200 m. (a) Draw a free-body diagram of the bird. (b) How much tension does the bird produce in the wire? Ignore the weight of the wire.2. this problem...

Homework Statement Use KCL and KVL to determine the currents I1 to I3 in the circuit below: Homework Equations Ʃv_{n} = 0 Ʃi_{n} = 0 v=irThe Attempt at a Solution I got two different answers for I_{1} using the two different laws. I'm not sure if I'm doing it right. KVL @ loop 1: -18 + 6 +...

A cylinder, open at both ends, laying flat level is to be filled with a substance that will harden as cement.One end has a 90 elbow attached at one end in order to fill cylinder.The cylinder is 25 ft long and 1 ft in diameter.Will gravity alone take the fluid to the very end of the cylinder...

Homework Statement A dot on the floor with a diameter of 2cm. A table that is at a distance of 46cm horizontally from the center of said dot. The table is 90cm tall. The meat of the problem: A ping pong ball rolls off an incline plane (a wooden board) that is on top of the table. The...

I was just thinking, are Newton's laws of motion most fundamental, or can they be reduced to something even simpler?

Homework Statement A meteor of mass .25 kg is falling vertically through Earth's atmosphere with an acceleration of 9.2 m/s. In addition to gravity, a vertical retarding force (due to the frictional drag of the atmosphere) acts on the meteor. What is the magnitude of this retarding force...

Consider a train moving at speed 's' and there is a charge particle at rest relative to the observer at train. The second observer on a ground see the charge particle and observer moving relative to him, and infer the existence of a magnetic field strong enough that its field is significant at...

a mass of m=6 kg is free to move without friction on a body with a mass of M=18 kg at an angle of theta=32 deg. M is placed on a friction free table. At the moment t=0 m is released from rest from the top of M at an height of H=4m . At what moment does m reach to the table? I'm uploading...

I have two questions. First, Paul Davies stated that the" Great Rule Book of Nature" would fit comfortably onto a single page. Is there a reference for these laws of physics? Second, the velocity of light is a fundamental constant. Has anyone analyzed what would change if the value were...

Some time ago I had a thought regarding turning rules in the US, back when right turn on (a) red (light - unless otherwise marked) was becoming universal. If U-turn was legal on the cross street, then by smoothing out a sequence of legal maneuvers: - left turn on red should be legal (right...

At the instant that one-fourth of block 1 remains on block 2, x2+l=x1+(l/16). For days trying to figure out how this equation derived from. Thank You. http://img15.imageshack.us/img15/3926/kotak.jpg

We all know that Newton's laws of motion are only valid in an inertial frame of reference. Our Earth is a rotating frame of reference, so Newton's laws of motion must not work anywhere on the surface of the planet. Do you agree?

Homework Statement Sometimes i got a question with homework if i can prove something. I got a book where the tolled me to use truthtables to see the outcome : For example : (notP V Q) <=> (P => Q) P Q | notP | notP v Q | P=>Q | (notP V Q) <=> (P => Q) 0 0 | 1 | 1...

"With the laws of physics you can get Universes?" Hi guys. I like Cosmology even though I'm not a professional. I encountered this short Fox News story: http://www.foxnews.com/scitech/2012/06/25/big-bang-didnt-need-god-to-start-universe-researchers-say/?intcmp=features I don't wish to...

Homework Statement A rod AB is shown in figure. End A of the rod is fixed on the ground. Block is moving with velocity √3 m/s towards right. The velocity of end B when rod makes an angle of 60o with the ground. Homework Equations The Attempt at a Solution I assumed that at any...

Homework Statement Given in the pic .. . Homework Equations F=mg The Attempt at a Solution i think block 2 hitting wedge will take place 1st as the direction of displacement of B1 is perpendicular to 'g' .. . but i don't think that's a logical answer please answer and explain why

kirchhoff's laws

The first law seems obvious, plug in 0 for acceleration and you get 0 force. Therefore for something to accelerate there needs to be some net force. Also, wouldn't the third law have to be true if energy is conserved at all times? Sorry if this has been asked before.

As we are being introduced to this new lesson, it gets difficult sometimes to indicate which component of either (linear or angular momentum) is conserved. Is there a strict rule to help me indicate which is which? Hmm, if not, can you give me the logical way through it? Thanks in advance...

Hello. I read recently that the law of conservation of energy can be violated for very short time intervals, according to the uncertainty principle. Apparently, this fact gives rise to virtual particle production from the vacuum. Once we accept that the uncertainty principle allows the laws of...

Homework Statement Water with mass density ρ are being shoot from a jet with cross sectional area A and velocity v0 at a man with mass m0. 1. Find the force acting on a man at rest (assume all the water are absorbed in the clothes) 2. Find the force acting on a man escaping at velocity v<v0...

Homework Statement Comet Halley approaches the Sun to within 0.570 AU, and its orbital period is 75.6 yr. (AU is the symbol for astronomical unit, where 1 AU = 1.50 x 1011 m is the mean Earth-Sun distance.) How far from the Sun will Halley's comet travel before it starts its return journey...

In Reif's book Fundamentals of Statistical and Thermal Physics, he labels two formulas as the Stefan-Boltzmann Law. They are both involve T^4 but the constant is different. In one, on page 376, the law is given as (pi2/15)*(kT)4/(c*hbar)3. The other, on page 388, is...

I'm reading about how the chemistry kinetics equations are derived and here's something I don't get. How does this: http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/Grafik/ord1-6.gif get turned into this: [A] = [A]_{0}*e^{-kt}? When I try to derive it, I...

Homework Statement Studies of the relationship of the Sun to our galaxy—the Milky Way—have revealed that the Sun is located near the outer edge of the galactic disc, about 30 000 ly (1 ly = 9.46 1015 m) from the center. The Sun has an orbital speed of approximately 250 km/s around the...

This conceptual question really got me thinking but I'm not sure how I would explain it: Your friend has been studying physics. She tells you that because of Newton's Third Law, she exerts a force on the Earth opposite to the force that it exerts on her. this worries her a lot because she...

"Simple" Newtons laws question ? At time t = 0 a particle of unit mass is projected vertically upward with velocity v_0 against gravity, and the resistance of the air to the particle's motion is κ times its velocity. Show that during its flight the velocity v of the particle at time t is...

Homework Statement Two Objects are hung from strings. The top object (m1) has a mass of 18 kg and the bottopm object (m2) has a mass of 12 kg. Looks like this...

Homework Statement A physics student playing with an air hockey table (a frictionless surface) finds that if she gives the puck a velocity of 3.44 m/s along the length (2.73 m) of the table at one end, by the time it has reached the other end the puck has drifted 2.08 cm to the right but...

Homework Statement Find current flowing through E1 ( find I1). Homework Equations I see 6 currents, atleast until the capacitor is charged, what i find confusing are the branches without any resistance and they seem to mess up my equations. The Attempt at a Solution 1st kirchhoff's law...

Back again with another problem. These transforms are difficult... Homework Statement Had to take a screenshot: http://i.imgur.com/LM38A.png The Attempt at a Solution His instructions are to take the Laplace Transform of each of Kirchhoff's laws. However, when we do, nothing useful comes...

1. Sean the skier is headed for a rough patch of snow with the coeffcient of friction 0.20. Find his acceleration if his mass is 50 kg. 2. F=ma, coeffcient of friction=Ff/Fn 3. Fgravity = 490.5 using the equation coeffcient of friction=Ff/Fn we get 0.20 = Ff/490.5 which equals Ff = 98.1 This is...

Application of Newtons laws (Friction related) check my solutions please :) Dont forget to check the diagram, as it will probably help you see the problem correctly, don't worry, no need to download diagram attachment to view it. Homework Statement A child pushes a block of wood with a...

Newton's third law says that every force X exerts onto Y, Y exerts and equal and opposite force onto X. Ergo, if I'm standing on my linoleum floor, I'm exerting a force equal to my weight (mass x force of gravity) onto the floor and it's exerting an equal and opposite force on to me. However...

The "stand your ground" laws Considering the current controversy in Florida over the death of a minor and what defense the killer may (or may not) use, here is some information from Wikipedia about the law: “A “stand-your-ground” law states that a person may use deadly force in self-defense...

I just got Spivak's calculus today, and I'm already stuck on the prologue problems: 1. The problem Find all x for which (x-1)(x-3)>0 2. The attempt at a solution We know that if ab>0, then either a>0 and b>0, or a<0 and b<0. Thus, if a=(x-1) and b=(x-3), then either (x-1)>0 and...

Hi, Based on Kurt Godel's incompleteness theorem, may be we could never understand the Universe completely because all our knowledge originated from within the Universe itself. Is it a valid application of the incompleteness theorem?

(1)A "swing" ride at a carnival consists of chairs that are swung in a circle by 10.0 m cables attached to a vertical rotating pole at an angle of 60 degrees with respect to the pole. Suppose the total mass of a chair and its occupant is 200 kg. (a) Determine the tension in the cable attached to...

Hi, I was wondering if anyone could tell me if these 4 following statements are correct? 1. V increases as a particle nears a proton 2. V decreases as a particle nears an electron 3. U increases as a particle moves in opposite direction of Electric Field 4. U decreases as a...

A car which is originally at rest accelerates down a road with a net force of 32000 N acting on a 1980 kg car. At t = 12 seconds the driver slams on the brakes to avoid hitting a deer. Calculate the distance traveled by the car. Coefficient of kinetic friction for the rubber on pavement is...

Homework Statement mass of the Earth = 5.97 * 10^24 kg Polar Radius of Earth = 6.36 * 10^6 m Satellite = 1.08 * 10^3 Kg Altitude = 2.02 * 10^7 m 3) for any object orbting around a primary body R^3 ∝ T^2 where R is the radius of the orbit and T is the time period for the orbit. show that...

So anytime I've seen textbooks explain integrated rate laws, they usually start with a reaction of the form A -> B and then from there say, if we know the reaction is first order with respect to [A] then: v = -d[A]/dt = k[A] And then subsequently integrate this to find ln[A]/[A]i = -kt...

Homework Statement A 89.6 kg man steps off a platform 4.52 m above the ground. He keeps his legs straight as he falls, but at the moment his feet touch the ground his knees begin to bend, and, treated as a particle, he moves an additional 0.88 m before coming to rest. Treating our rigid...

Homework Statement John (mass = 80 kg) rests on the top face of a light cube (mass = 0). A light rope passes horizontally from him over the front edge, and vertically down to Brian (mass = 60 kg) who hangs in contact with the front face as shown. The cube rests on a horizontal surface and...

Homework Statement Calculate the acceleration of a car given the fuzzy die hanging from a string attached to the roof of the car is deflected 15degrees to the vertical. The mass of the die is 250 g. Homework Equations F = ma Fg = mg and possibly many more! The Attempt at a Solution I don't...

1. Star X has a surface temperature of 10,000 K. How much power does it emit per square meter? Enter numbers only. Do not enter units (watt/m2 is assumed) 2. Star X has a surface temperature of 10,000 K. What is the wavelength of the dominate electromagnetic radiation that Star X emits? Enter...

Hello, 1a) Generally, would anyone mind discussing what laws of nature (aka. physical laws, physical principles, scientific laws, etc.) are? 1b) Are they only to describe phenomena, i.e., interactions, behaviors, etc.? 1c) Or do any describe why certain entities are similar? Note: by...

Problem: "One 2.80kg paint bucket is hanging by a massless cord from another 2.80kg paint bucket, also hanging by a massless cord" a. Calculate the tension in the upper cord when the two buckets are pulled upward with an acceleration of 1.54m/s^2 by the upper cord. T1 = upper cord's tension...

Homework Statement When you turn on an electric heater, such as "burner" on a stove, its temperature increases rapidly at first, then more slowly, and finally approaches a constant high temperature. As the burner warms up, heat supplied by the electricity goes to two places. i.) Storage in...

Free body diagrams for system A that consists of two blocks and for system B with one block: http://i7.photobucket.com/albums/y260/filipina4eva92/1329082077750.jpg acceleration and net force from the systems: http://i7.photobucket.com/albums/y260/filipina4eva92/Unknown.jpg frictional force...