Law Definition and 999 Threads

When considering the magnitude of the magnetic field at a certain point (##P##) away from an infinite/finite wire, I can't understand how an infinite wire would generate a stronger magnetic field (##B##) in contrast to a finite wire that has the same dimensions and current applied, at the same...

The integral form of Maxwell's equation pertaining to induced electric fields is: ∮E(t0)⋅dℓ= −dΦ(t)/dt|t=t0Say for a long time, in some circular region there has been no B or E fields present. Then, there is a sudden constant increase of B field introduced in the middle. I know that information...

I would really appreciate some clarification about how to draw graphs showing changing flux and induced EMF. I understand that there needs to be a 90 degree phase difference as the EMF is a maximum when the flux has the greatest rate of change. However, our exam board says that the EMF can be...

Homework Statement Explain what happens in the following situation: You have a loop in the form of a circle and there is a varying magnetic field inside that loop as the following picture illustrates: Homework Equations Faraday's law lorentez force The Attempt at a Solution I first thought...

Why do all the volume temperature curves of an ideal gas intersect at the same point on the temperature axis ?

A varying magnetic flux causes an induced voltage (according to Faraday-Lenz law) that generates a current that generates a magnetic field that generates another magnetic flux in the same circuit. Does the Faraday-Lenz law include this self induction? In other words why can't we take that...

Are exothermic reactions violation of law of conservation of mass , because energy and mass are equivalent? Please clarify!

Hello, I'm going through Kirchoff's second law, and stumbled across this example on this page: In the image above, you can see that the blue arrows (both arrow 1 and arrow 2) indicate the direction that the current goes in. However, I am wondering why the current cannot go as per the red...

3. The Attempt at a Solution My thinking is that if cross sectional area of the cords increase wouldn't the cords be heavier and thus it would require more work to pull/stretch the device? So more work is done? (But the answers say less work is done because there is a smaller extension/won't...

Raoult's law: P = xP* , combined with Dalton's law becomes y = xP*/P Henry's law: P = kx, combined with Dalton's law becomes y = kx/P Relative volatility: y = ax/(1 + (a -1)x) Raoult's law and Henry's law are linear when temperature and pressure are kept constant. But if we vary the temperature...

How can we prove the law of conservation of mass ? I said prove not the verification, how lavoiser decided that yes this law is followed by every chemical reaction, is there a proof

The Attempt at a Solution [/B] I know that spring A shows elastic deformation since it returned to its original shape once the stress removed and spring c shows plastic deformation and has been permanently extended so it won't return to its original shape. BUT, I'm struggling to complete the...

According to Ohm's law, "Physical conditions remaining the same, the electric current flowing through a conductor is directly proportional to the potential difference across the two ends of the conductor" I have two conceptual queries: FIRST When the ends of the conductor are not connected to...

I keep reading articles that assert that spiral galaxies would fly apart if it were not for the presence of a dark matter halo. The observation that rotational speeds vary little with distance from the center is usually cited as the 'proof' of dark matter since this behavior would otherwise...

Is it possible to calculate the rate of change of n with respect to rate of change of Pressure and rate of change of Temperature with V unknown but constant by PV = nRT? Rate of change of Pressure and rate of change of temperature can be measured. R and V are constants.

Homework Statement A mass ##m## on a frictionless table is connected to a spring with spring constant ##k## so that the force on it is ##F_x = -kx## where ##x## is the distance of the mass from its equilibrium position. It is then pulled so that the spring is stretched by a distance ##x## from...

Homework Statement Find the total time, t, that an object takes to reach the surface of the Earth from a distance, D, using the Law of Gravitation: $$F_{g} = \frac{GMm}{x^2}$$ R is radius of Earth D is distance from surface R+D is total distance from center of masses ****** One Dimension...

Homework Statement Hello, I am not asking for the answer to an example, rather how the book got some numbers. The problem is an example from the book and shows me the solution but does not show the steps. Given: The compressed air tank has a volume of .84 ft^3. The temperature is 70 F and the...

I'm working on induction at the moment, and the math makes sense, but Lenz's Law is giving me trouble. Does anyone have an easier way (relatively) of remembering the directions of emf? Any advice is appreciated.

Hi, Just wanted to know how can we attribute the kepler's law of areas to a radially directed force?

Homework Statement [/B] I need to help solving part a) Homework Equations [/B] $$v= \frac{2\pi}{T}$$ $$(\frac{T_1}{T_2})^2 = (\frac{r_1}{r_2})^3$$ The Attempt at a Solution I'm not sure where to begin really. One approach I tried was getting T_1 in terms of v_0 and plugging it into...

Homework Statement There's a disc with a current density surface σ, with radius R and angular velocity ω Find the B Homework Equations α = vσ=ωrσ The Attempt at a Solution I'm having problems understanding why the cross product gives αr

Firstly I appologize, that I am not native english speaker and I don't study physics(but cybernetics we are getting just some general knowledge about physics), but hopeffuly I will write this right. Homework Statement We know that inside of a conductive object is protected from influence of...

Faraday's law talks about the change in the flux through a loop, but I never see how people take into account the change in the flux due to Faraday's law itself and I am wondering if that leads to a contradiction. For example when calculating the current through a physical loop with area A and...

I have a question on convention regarding the universal law of gravitation formula. Sometimes the distance is represented with the lowercase r and sometimes with the uppercase R. Why is it listed two different ways? I am thinking that r is the total distance and R is the radial distance, no...

Homework Statement (introduction course of university physics) A 25- L container holds ideal hydrogen (H2) gas at a gauge pressure of 0.25 atm and a temperature of 0°C. What mass of hydrogen gas is in this container? The ATOMIC mass of hydrogen is 1.0 g/mol, the ideal gas constant is R =...

Say we have a tire filled with air (equal to ambient air surrounding it in every way). pressure on the gauge is 0. Then, we pressurize it to 1 ATM (15psi). If we heat the tire , the air will be heated and expand based on gas law, or is there a factor that changes it based on the air's...

I couldn't remember which number was which in Newton's laws of motion, and so I clicked the first link I found, but to my amazement it seems that while Rice University got the number right, they got the facts of how it works wrong. Ironically it seems they have made the same mistake as that...

Homework Statement Using Kirchov’s Current Law (KCL) at the top node of the circuit, write the differential equation for the membrane voltage (Vm). Solve for Vm(t) symbolically,assuming that all other voltages, all resistances, and the capacitance are constant Homework Equations Current law...

Hello everyone! I'm currently trying to calculate electric forces between two objects, so for that I of course need Coulomb's Law. I understood its equation (etc.), but there are 3 things that I haven't found out yet: -How exactly can you find out or calculate what amount of charge an object...

Hello Forum, The speed of water exiting from a side narrow hole at depth h in a large bucket is given by ##v=\sqrt{2gh}##. This result is obtained applying Bernoulli's equation along a streamline that goes from the top free surface to the drain on the side of the bucket at depth h. The water...

Is the law of cosines the only equation that expresses the relations between the sides and angles of a triangle? (Other than the law of sines). For example: Suppose we have a triangle and sides a,b and the angle opposite of c is known. Then invoking the law of cosines, we know that c sq = a...

Homework Statement I am looking at the following system: It shows a pore/tube (B) which is attached to a reservoir A. The fluid in reservoir A has a non-zero velocity in the horizontal direction, but I assume that the tube B is so long that the velocity there is unaffected and still zero...

Is the law of conservation of momentum valid in non isolated system . What is an isolated system? My teacher confuses me that the law is valid in an non isolated system . They even say that when we say about the isolated system (meaning they are present ) we do not consider the air resistance...

I was just wondering, what if an object is placed in our solar system, will it revolve around the sun? If yes, will it have a centripetal acceleration too?

Consider two objects, "A" and "B", each having mass 1kg. Object "A" moves downward towards object "B" and collides with the extended arm of object "B". Let's say for the sake of argument that during this collision object "A" lost one unit of momentum and 0.5 joules to object "B" (This value does...

Homework Statement The position of a 49 g oscillating mass is given by x(t)=(1.8cm)cos12t, where t is in seconds. Homework Equations k=mg/x The Attempt at a Solution I've tried working this problem multiple different ways and it is just not working for me. I used k= (.049*9.8)/.018 Is this...

Why is it that the induced emf opposes the change in magnetic flux? Is it to follow the law of conservation of energy?

Homework Statement Snell's law is: $$\frac{\sin\theta_1}{c_1}=\frac{\sin\theta_2}{c_2}$$ $$\frac{c_1}{c_2}=n_{12}$$ Express ##\theta_2## as a function of ##\theta_1## Find the largest value of ##\theta_1## for which the expression for ##\theta_2## that you just found is...

Homework Statement Three charges, q1, q2, and q3, lie in a plane, as shown below. Find the net force on charge q2 (please refer to attachment for diagram) Homework Equations F= k x q1q2/R^2, knowledge of trig functions and separating x and y components The Attempt at a Solution So I found the...

A cone-shaped water tank is given by V(h)=\pi(h-\frac{h^2}{3}+\frac{h^3}{27}) Show using Torricelli's law law that -2\sqrt2\pi(\frac{1}{\sqrt{h}}-\frac{2}{3}\sqrt h+\frac{1}{9}h^{3/2})\frac{dh}{dt}=1 What I have done so far: V'=\frac{1}{9}\pi(h-3)^2h'

A cup of tea is removed from the fridge and left on a desk. The temperature of the room is constantly E and T(t) represents the temperature of the tea after t minutes. dT/dt = K(E-T) Z(t) = E-T(t) How do I find the general form of Z and T?

I am pretty confused about how to write Navier-Stokes Equation into conservation form, it seems that from my notes, first, the density term with the pressure gradient dropped out. and second, du^2/dx seems to be equal to udu/dx. Why is it so? I attached my notes here for your reference.

Can we find the natural frequency of water's molecules by using of Newton's law of cooling and resonance phenomena?

Homework Statement This problem is Problem 2.24 from Fundamentals of Electric Circuits (5th edition). The problem is as follows: Homework Equations KVL, KCL The Attempt at a Solution In the official solution, they assume that the total current in the lefthand loop is ##I_o##, whereas the...

I am learning principle of optics written by Born&Wolf and confused with the method to derive Snell's laws and law of reflection. In the textbook,##v_1## is the speed of light in mediator 1 and ##v_2## is the one in mediator 2. ##{\vec s}## is the direction of light and ##{\vec r}## is the...

Homework Statement Mass =0.908kg Area= 5.3 x 10^-4 m^2 2. Attempt This was for a lab I am doing on gas laws. Its asking to calculate exerted pressure in kPa. This is what I've done so far : F= 0.908kg * 9.8m/s^2 = 8.8984N Pressure = Force/ Area Pressure= ( 8.8984N) /( 5.3 * 10^-4...

Homework Statement THIS PROBLEM CONSISTS OF NOTHING MORE THAN WHAT IS BEING STATED (NO VALUES, NO EQUATIONS, NOTHING) THIS IS A WORD PROBLEM WHERE NO CALCULATIONS ARE TO BE MADE: A mass hangs from a vertical spring and is initially at rest. A person then pulls down on the mass, stretching the...

Homework Statement I'm having trouble / uncertainties about the third missing angle (from left to right) in the picture. The first angle of reflection was easy as it's just 34 degrees as well and I used snell's law rearranged to find the first angle of refraction as 13.36 degrees from the...