Laws Definition and 1000 Threads

About a month ago 2 police officers were killed in a "Gun and grenade attack" in Greater Manchester, UK: http://www.telegraph.co.uk/news/uknews/crime/9550417/Two-female-police-officers-shot-dead-in-Manchester-as-man-arrested.html This lead to the inevitable re birth of the topic "Should we...

Homework Statement You have a fuzzy dice with mass .2kg hanging from the rear view mirror. When you step on the gas the dice makes an angle of 25 degrees. what is car's acceleration? Homework Equations F=ma...? Fr=mac..? The Attempt at a Solution Im really not sure where to start...

Homework Statement In recent years, a number of nearby stars have been found to possesses planets. Suppose, the orbital radius of such a planet is found to be 4.9 1011 m, with a period of 1280 days. Find the mass of the star. Homework Equations T^2=4pi√((r^3)/Gm)) The Attempt at a...

Homework Statement A horizontal wire holds a solid uniform ball of mass m in place on a tilted ramp that rises 35.0° above the horizontal. The surface of this ramp is perfectly smooth, and the wire is directed away from the center of the ball.(a) How hard does the surface of the ramp push on...

Homework Statement Given two batteries in parallel, one of 10V and 5Ω, and the other of 5V and 2Ω, which is attached to a 3Ω resistor, find the current that flows from the 10V battery, if the system described above is connected to a 20 resistor. Homework Equations Kirchhoff's two laws...

Hi, I was trying to remember all the laws in physics needed for my grade(10) but I couldn't remember except Ohm's law and every thing related to oscilloscope but I didn't remember laws related to work and force. Can anybody help me please. Thanks.

Homework Statement A gardener pushes down on the handle of a lawnmover, applying a force of 250N. The handle is inclined at an angle 45* to the horizontal. If the coefficient of the kinetic friction between the wheels of the lawnmower and the ground is 0.40, what is the acceleration of the...

I will try my best to explain this question: Block S (the sliding block) with mass M = 3.3 kg, is free to move along a horizontal friction-less surface and connected, by a cord that wraps over a friction-less pulley, to a second block H (the hanging block), with mass m = 2.1 kg. The cord and...

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...

I have for a while been trying to understand the setup of this equation in calculating the collision flux of a gas through a given rectangular surface of area A: Number of collisions in a time interval Δt is (\frac{N}{V})AΔt\int^{∞}_{0}v_{x}f(v_{x})dv_{x} where f(v_{x}) is the fraction of...

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 A 15kg block is attached to a very light horizontal spring of force constant 500 N/m and is resting on a frictionless horizontal table. It is struck by a 3kg stone traveling horizontally at 8m/s to the right, whereupon the stone rebounds at 2 m/s horizontally to the left...

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...