Law Definition and 999 Threads

Homework Statement Due to formatting problems, I have attached the problem below. Homework EquationsThe Attempt at a Solution Plotting the appropriate graphs and based on linearity, I have determined that the reaction is first order with respect to [O2] and second order with respect to [NO]...

Hey I was hoping someone could be me a succinct method of knowing what form of the Ideal gas law I need to use and in particular the different R's associated with each form. Form my Thermodynamics class we use PV = nRT Pv = RT PV = mRT Little v being the specific volume (which changes the R...

1. Homework Statement Due to formatting problems, I have attached the question below. The attempt at the solution: I am not sure how to deal with the hydroxide ion since it is written above the arrow. I believe that this signifies a species not included in the overall reaction but is...

Hi Guys, I solved two questions below. Just need some feedback to make sure I solved them correctly. Thanks a bunch. 1. Homework Statement A car of mass 1.4 tonnes (1400 kg) traveling down the highway at 120 km/h has a F air of 1800 N acting against it. What force must be applied by the...

In hydraulic lift utilising pascal law, larger piston area is A1 and the smaller piston area is A2 mass in = mass out and volume in = volume out (in-compressible),so A1*x1=A2*x2 (let x1 and x2 are displacements of respective pistons) A1*V1 =A2*V2 (on differentiation gives continuity...

Homework Statement I keep getting confused about this part of Gauss' law. Is the da on the left side the surface area of the the Gaussian surface? and on the right side when I am integrating. I say that q = the charge density multiplied by something. Is that something surface area of the...

Homework Statement A 20-kg block with a pulley attached slides along a frictionless ledge. It is connected by a massless string to a 5.0-kg block via the arrangement shown in Figure. (a) draw complete free body diagrams for the masses and Find (b) the acceleration of each block and (c) the...

Hey guys is my solution correct for the question below? 1. Homework Statement Consider a 5.0 kg watermelon that is being accelerated at 2.0 m/s2 [up] by a cable. Find the tension in the cable. Homework Equations Fcable = m.a The Attempt at a Solution Fcable = m.a = 5.0 kg(2.0) = 10N

Homework Statement In a sealed container is Helium ##M_{He} = \frac {4kg} {kmol} ## with a pressure of ## p_{He} = 4bar##. now is Methan put isothermic inside the container till both the methan and the helium mass are equal( ##M_{CH4} = \frac {16kg} {kmol} ## Calculate using the ideal gas law...

Can someone please help me solve this question below. 1. Homework Statement How much force is needed to push a 20 kg box across a floor at a constant speed of 0.5 m/s [forward] against a frictional resistance of 4 N? Homework Equations Fnet = m.a The Attempt at a Solution Since the velocity...

I have to design a track for a skate boarder that is 50% efficient (friction must be present) from the start of the skater's drop-in, to his furthest point along the track. My skater's mass will be 75kg efficiency=energy output/energy input x100% I am not really sure where to go next and how...

Homework Statement A beam of thermal neutrons (K = 0.025 eV) scatters from a crystal with interatomic spacing 0.45 nm. What is the φ angle of the first order Bragg peak? (as defined in figure 5.11, φ and the scattering angle add up to 180 degrees). Homework Equations nλ = 2dsinθ = DsinΦ d...

I have a problem which reads: A frictionless pulley with zero mass is attached to the ceiling, in a gravity field of 9.81 m/s2 . Mass M2 = 0.10 kg is observed to be accelerating downward at 1.3 m/s2 and I have a solution which tells me to solve the problem use Newton's 2nd law: m1a1 = T1 -...

Simple premise: take ohms law with a purely resistive ac circuit. 1 volt through in series with a 2 ohm resistor, I have 0.5 amps of current. I want to maintain constant power. In practice, "how low can I go" with the voltage to increase the current? There's probably many variables I'm missing...

<Moderators note. Moved from the quoted thread to avoid detracting> Newton third law does apply in magnetism, and this is proved by applying the conservation of momentum principle. This will be clearer when the causes/origin of the magnetic force is understood as described in the work "Two new...

Hello. Resistive Ohm's law is famously known as V = IR. We can derive its microscopic version as being followed. V = El, where E and l are, respectively, an electric field and a resistive load length over which a voltage drop V is developed. I = JS, J and S are a current density and a...

If a magnet was going fast enough as it approached/entered a copper tube, could the current induced in the tube via Lenz's Law be high enough to melt or even vaporize the tube?

Homework Statement I need to research Hess' law, but I can't find a simple explanation. I know that the enthalpy change between the reactants and products is the same as the enthalpy change between the reactants and something else, and between that something else and the products, but I don't...

Homework Statement Question 1. A triangular prism of mass M is placed one side on a frictionless horizontal plane as shown in Fig. 1. The other two sides are inclined with respect to the plane at angles a1 and a2 respectively. Two blocks of masses m1 and m2, connected by an...

Hello. I have several confusions regarding Faraday's law of induction. EMF = \int_{}^{} {\vec E \cdot d\vec l} = - \frac{{d\Phi }}{{dt}} = - \frac{d}{{dt}}\int_{}^{} {\vec B \cdot d\vec S} . It means that If the magnetic flux Φ through the closed conducting loop changes in time, electric...

22. According to Lambert's law of absorption, the percentage of incident light absorbed by a thin layer of translucent material is proportional to the thickness of the layer. If sunlight falling vertically on ocean water is reduced to one-half its initial intensity at a depth of 10 feet, at...

Homework Statement You come across a dead body at 3 PM. Its temperature is 83.6 F. 30 minutes later its temperature is 78.6 F. How long was the guy dead before you found him? Homework Equations ##\frac{dT}{dt}=-k(T-Tair)## T(0) = 83.6 F T(0.5) = 78.6 F The Attempt at a Solution This is a...

Hi. All derivations of the (ideal) transformer equation ##\frac{U_p}{U_s}=\frac{n_p}{n_s}## use Faraday's law of induction $$U=-n\cdot \frac{d\Phi}{dt}$$ for primary and secondary and equate the change of flux ##\frac{d\Phi}{dt}##. Until now, in my textbooks it was always like this: Electrical...

For class we have been asked to show how the first law of thermodynamics dU=dQ+dW can be shown to be dQ=(CV/R)*VdP +(Cp/R)*PdV I have an answer, but am hesitant to say it is a final answer. I will admit that while doing the problem I had trouble following what I was doing. Hence my...

A student in my physics class posted, in a group, a wrong answer to a question. The situation was: A plane has a wire extended between the tips of its wings and flies through a magnetic field, perpendicularly, while accelerating. The question was: What will be the induced current? His answer...

Is the Hubble's law(recessional velocity linearly proportional to distance) valid for all cases even when the spacetime is curved? Is there a nonlinear model for Friedman models or it's always linearly proportional?

Homework Statement Problem: A 12.0-kg block is pushed to the left across a rough horizontal surface by a force that is angled 30.0◦ below the horizontal. The magnitude of the force is 75.0 N and the acceleration of the block as it is pushed is 3.20 m/s^2 . What angle does the force exerted on...

Homework Statement If I have the circuit below, and the white circle is Infinite Coil with current of I=xt, Counterclockwise, with a radius a. from Faraday's law we know that will be Electromotive force . 2. Homework Equations what the EMF in needed to stop the current at the middle R ? The...

Homework Statement An isolated conductor has a net charge of +14.0 × 10- 6 C and a cavity with a particle of charge q = +4.30 × 10-6 C. What is the charge (a) on the cavity wall and (b) on the outer surface? Homework EquationsThe Attempt at a Solution So I understand that B is just adding the...

I wonder why Newton second law, define force as mass x acceleration, acceleration is the second time derivative of displacement, why he didn't define the force as mass x higher order time derivatives of displacement

Hello! I have the equation FM = qvBsinθ . As the end result, I am trying to figure out what B I need to change θ even a little bit. To do that, I was planning to find the minimum B by differentiating B=(μe/4π)(qv x R / R3) in terms of R and setting it equal to zero. . I am assuming that this...

Homework Statement 3 charges are placed like shown: Q1 __4cm____ Q2 ______6cm___________Q3 Q1=-2nC Q2= 1nC Q3= 3nC Find the resultant force and its direction upon the charge Q3. Homework Equations F=k0*(Q1Q2)/r2 k0-constant, equals to 9*10^9 r-distance The Attempt at a Solution...

Hello everyone, I am working on understanding how Kirchhoff's Radiation Law applies in the real world. Basically, the absorbed solar radiation must equal the thermal radiation if a surface is to be at equilibrium. Certain relationships follow from this assumption, namely, for an opaque...

Knowing that Gauss' law states that the closed integral of e * dA = q(enclosed)/e naut, how would you find exactly what A is in any given problem? I know it varies from situation to situation depending on the geometry of the charge. For instance, I know that for an infinite wire/line of...

Homework Statement Figure (a) shows charged particles 1 and 2 that are fixed in place on an x axis. Particle 1 has a charge with a magnitude of |q1| = 19e. Particle 3 of charge q3 = +16e is initially on the x axis near particle 2.Then particle 3 is gradually moved in the positive direction of...

Homework Statement A 600 line/mm diffraction grating is in an empty aquarium tank. The index of refraction of the glass walls is [n][/glass] = 1.50. A helium-neon laser (lambda=633 nm) is outside the aquarium. The laser beam passes through the glass wall and illuminates the diffraction grating...

Homework Statement The extension in a string, obeying hooke’s law is Y when wave velocity in it is V. if extension is increased to 1.5Y, then wave velocity V’ becomes? 1) V' =V. 2)V'= 1.22V . 3)V'=1.5V. 4) V'=0.75V. Homework Equations wave velocity= frequency*wave length. The Attempt at a...

Homework Statement Homework Equations Ex=1/k*1/(a^2/2)*1/(sqrt2)*cos(theta)*(sum of charges) Ey=1/k*1/(a^2/2)*1/(sqrt2)*sin(theta)*(sum of charges) The Attempt at a Solution So first off I can see that I don't need to calculate the force in the x direction as each q cancels out when...

<Mentor's note: moved from a technical forum, therefore no template> My teacher made this question: Iceman is sliding down a 10.0 x 10^(-8) nm ice that is inclined at 20.0 degrees with respect to the horizontal. Iceman is initially at rest. The coefficient of kinetic friction between iceman's...

Hi. If a planar wire loop is moved through a homogeneous magnetic field (field lines perpendicular to the loop plane) with constant velocity and no rotation, Lorentz force will move some electrons to one side of the loop, creating a potential difference. But how does this work with Faraday's...

1. For arbitrary real numbers a & b, exactly one of the three relations hold: a < b, a > b, a = b. How do I state this more formally while also being correct?2. The attempt at a solution a, b ∈ ℝ ( (a < b) ⊕ ( a > b ) ⊕ ( a = b) ) From this I made a truth table 2^3 entries long, and what we...

I've learned that in a wire with a current flowing through it, a magnetic field is produced, and that to determine the direction of the fields, one could match their thumb with the direction of current and curl their fingers around the wire as shown in the link below. I also learned that in Biot...

COULOMBS LAW F= K Q1 Q2 / R2 How would I solve for Q1 and Q2?

I've been trying to study for my final and I can't seem to figure out how is this suppose to work. 1. Homework Statement A wall (m infinite, v=0) hits a car (m=2600 kg; v=142 km/h). The car becomes deformed and the crush zone (0.7 m) is compressed. Calculate the corresponding acceleration...

Homework Statement A cylinder fitted with a frictionless piston contains 5.0×10-4m3 of an ideal gas at a pressure of 1.0×105 Pa and temperature of 300K. The gas is then (i) heated at constant pressure to 450K, and then (ii) cooled at constant volume to the original temperature of 300K. The...

Ecosystems are open systems, they receive solar energy and other materials from outside the ecosystem and migration of animals is also witnessed. I read Physics uptil class XII and have done a bit of research on google books and have come across these three books: 1.Towards a Thermodynamic...

Dear all, I've never really understood how exactly Liouville's theorem about time-conservation of phase space volume can be reconciled with the second law of thermodynamics. Recently I came across this popular article, http://www.necsi.edu/projects/baranger/cce.pdf "Chaos, Complexity, and...

I have a doubt on this calculation of magnetic field in presence of displacement current. Consider a capacitor of radius ##R## and with plates at distance ##d## being charged: there is a displacement current in it. Suppose that I want to calculate the magnetic field ##B## at a distance ##r <...

Hello, I’ve been trying to derive Posseuille’s Law and I’m very close. However there seems to be a small difference between my concluded formula and the real one but I don’t know why. Here’s what I get: Picture a cilindrical tube with a radius ##R## in which a fluid is flowing. From what I...

Wow, just wow. Only just stumbled across this so haven't looked at any formal studies but still, wow!