Net Definition and 1000 Threads

Dear all, I'm trying to think about applying the second law of thermodynamics to a system which is not isolated, but has an energy flowing inwards and an equal (!) energy flowing outwards, such that the total energy does not change (total energy flux is zero). Can we still apply the second law...

Homework Statement Two point charges ##Q_1 = 9 \mu##C and ##Q_2 = -16 \mu##C are fixed in space on a distance r=7cm. At what distane ##x_1## from the first charge, and ##x_2## from the second charge, should we place the third charge ##Q_3## so that net force on ##Q_3## is zero? make a sketch...

Homework Statement Calculate the net force on A.[/B] Homework Equations F=k . (q1 q2)/r^2 , k=9 x 10^9 Nm^2/C^2[/B]The Attempt at a Solution (9*10^9 Nm^2/C^2)(1,4 x 10^-6C)(7,2 x 10^-6C) / 1,7mm^2 = 0,0313. Could someone tell me what I am missing even if what i did is even correct. Thanks[/B]

MENTOR Note: Thread moved here from Classical Physics hence no template I have a question set that I need to be able to answer before my exam next month, I know how to answer all of them except this one. I get the feeling I'm being an idiot. Show that the simple harmonic motion solution of the...

Homework Statement Calculate the net force acting on the object indicated in the following diagrams. Show your work. 1) 2) Homework Equations [/B] The Attempt at a Solution 1) 8.0 N (north) + 10.0 N (south) - 8.0 N (south) + 10.0 N (south) = 2.0 N (south) c= [ (2.0 N) 2 +...

Homework Statement Calculate the net force acting on each object in the following diagrams. Show your work. Homework Equations [/B] The Attempt at a Solution c2= a2 + b2 - 2abcosC c = (a2 + b2 - 2abcosC) 1/2 c = [ (32.0 N)2 + (38.0 N)2 - 2 (32.0 N) x (38.0 N) cos 55° ] 1/2 c = 32.8 N...

Ques: If infinite number of charges placed along x-axis .At x=1, 1μC , x=2, 2μC, x=3, 3μC so on. Find the net force on charge 1μC placed at origin.Formula used (1/4πε)*q1*q2/r² Solved from this formula but stuck in a series

I find the common physics problem of accelerating boxes that are touching very confusing. (To be clear, boxes are on surface, force comes from one side and all boxes accelerate. Questions typically ask about magnitude of force between particular boxes). Once the boxes are accelerating, why is...

Hi all, Would it be possible to try to predict Pi by a neural net. So basically when you input 1 into the neural net you will train it to output 3. Next input 2 and train it to ouput 1. Etc... Next after training the net such that it will predict the first 1000 positions correctly would it...

Homework Statement A steam power plant consists of a boiler, a turbine, a condenser and a pump. The temperature of the inner walls of the boiler is 350oC and the temperature of the condenser cooling water is 20oC. During a certain interval of time, the heat added to the boiler is 2.9x106 kJ and...

Given this diagram: Two wires, having parallel and opposing current flows( Where ## I_1 = I_2 ##), creating opposing and equal magnetic fields near a ferromagnetic object(##F##), since the magnetic field of each wire is not uniform, I'm not really certain how to figure out the magnetization of...

The estimated annual maintenance cost associated with the delivery vehicle amounts to R14 000 for the first year that the vehicle will be used (payable at the end of the year). The annual maintenance cost for the subsequent two years will increase by 4% per year as a result of wear and tear...

Homework Statement So we have a horizontal bar. Distance = r Forces = F All numbers remain constant with the exception of the distance, denoted as r(set)() Length of bar = 1m F1 = 10N r1-1 = 0m r2-1 = .25m (behind the point of rotation) F2 = 5N r1-2 = 0.5m...

Homework Statement Homework Equations relevant equations are provided with each question below The Attempt at a Solution please check my solutions to ensure they are correct. thanks. a) [/B] b) Calculate net force: Fnet = FA + Ff + Fg Fnet = (1.20 x 104 N [up]) + (1.40 x 103 N [down])...

Homework Statement Three point charges are located on the positive x-axis of a coordinate system. Charge q1 = 1.0 nC is 2.0 cm from the origin, charge q2 = -3.5 nC is 4.0 cm from the origin and charge q3 = 6.0 nC located at the origin. What is the net force ((a)magnitude and (b) direction) on...

Homework Statement Is the direction of net force always in the direction of motion? The Attempt at a Solution I would say no because the net force could be equal/balanced for example if two kids were pulling on a stick 2 N left <---- . ----->2 N right the Total Net Force would be 4 N with...

Homework Statement Homework Equations The Attempt at a Solution 32° + 24° = 56° I used the tip-to-tail method to add vectors c = ([12 N]^2 + [15 N]^2 - 2 [12 N] x [15 N] cos124°)1/2 c = 23.9 N SinA/12 N = Sin124° / 23.9 N (i don't know how to solve this part) can someone please...

Homework Statement Homework Equations The Attempt at a Solution 8.0 N (north) + 10.0 N (south) = 2.0 N (south) i used the tip-to-tail method to add the vectors c = ([2.0 N]^2 + [17.0 N]^2 - 2 (2.0 N) (17.0 N) cos45°)1/2 c = 15.6 N SinA/17.0 N = Sin45°/15.6 N A = 40° Net force = 15.6 N...

Homework Statement Homework Equations The Attempt at a Solution c = ([32.0 N ]^2 + [38.0 N]^2 - 2 (32.0 N)(38.0 N) cos70° ) 1/2 c = 40.5 N (is this correct?) SinA / 38.0 N = Sin110° /40.5 N (im unsure how to solve this part) A = ?? net force = 40.5 N (East ? North) I am very confused...

Homework Statement At the instant illustrated, which best describes the angular momentum of the ball and net torque on the ball, as measured around the origin? L⃗ is in the kˆ direction, ⃗τ is 0. Homework Equations torque= (F)x(r) Tension in rope= (mv^2/r)+qvbThe Attempt at a Solution I am...

Homework Statement A four cylinder, four stroke internal combustion engine has a bore of 3.7 in and a stroke of 3.4 in. The clearance volume is 16% of the cylinder volume at bottom dead center and the crankshaft rotates at 2400 RPM. The processes within each cylinder are modeled as an air...

Homework Statement An 82 kg man drops from rest on a diving board 3 m above the surface of the water and comes to rest .55 s after reaching the water. What is the net force on the diver as he is brought to rest Homework Equations FDt = mv F = mg v^2 = vi^2 = 2aDx Dx = 3m Dt...

Homework Statement [/B] https://wcl.unr.edu/bbcswebdav/pid-634340-dt-content-rid-2875167_1/xid-2875167_1 So I am given the above image, and I am told to calculate the voltage in the circuit. Homework Equations V = IR R_net = (1/R_1 + 1/R_2 + ... + 1/R_n)^-1 for parallel resistors 3. The...

Physicists have observed the cosmic radiation background to conclude that the universe is flat (or within the margin of error of being flat). This means that the Universe contains the critical density needed to keep it flat, which is a mix of ordinary matter, dark matter and dark energy (I...

Homework Statement A closed surface with dimensions a = b = 0.302m and c=0.604m is located as in the figure. The electric field throughout the region is nonuniform and defined by E⃗ = (α+βx2)ˆı where x is in meters,α=4N/C, andβ=4N/(C·m2).? What is the magnitude of the net charge enclosed by the...

While watching lecture at Coursera, i tumbled over this fourmula Moment \mathbf{M}=\sum_{i=1}^{4}(\mathbf{F}_i\times \mathbf{r}_i+\mathbf{M}_i) where F is uplift force from a propeller, and M is drag moment for a propeller. But why they add drag moment(torque) like that? Maybe it will differ...

Homework Statement The figure shows a closed Gaussian surface in the shape of a cube of edge length 1.80 m. It lies in a region where the electric field is given by E= (2.86x + 3.82)i + 7.18j + 8.36k N/C, with x in meters. What is the net charge contained by the cube? Homework Equations ε0...

Homework Statement In the figure the four particles form a square of edge length a = 6.10 cm and have charges q1 = 6.35 nC, q2 = -17.9 nC, q3 = 17.9 nC, and q4 = -6.35 nC. What is the magnitude of the net electric field produced by the particles at the square's center? Homework Equations...

Homework Statement An airplane with a mass of 5.32 x 10^4 Kg accelerates down the runway at 1.76 m/s^2 [forward]. Calculate the net force acting on the airplane. Homework Equations Fnet=ma The Attempt at a Solution I did this by multiplying the two given values, but my answer was 93632N...

1. The problem statement: In the figure four particles form a square with edge length a = 2.44 × 10-2 m. The charges are q1 = q4 = 1.06 × 10-15 C and q2 = q3 = q. What is q if the net electrostatic force on particle 1 is zero? All variables and given/known data: The given variable are in the...

Homework Statement A car is going around a circular track at constant velocity. What direction is the net force acting on the car pointing to? Homework Equations Fnet = ma[/B] Fnet = m(v^2/r) --> don't really know if this will help me understand it, but if this will help me understand what's...

My question doesn't come from any homework, or from a text, or any course work. I am just curious, but horrible with physics. I am a falconer. I trap hawks and falcons for my hobby, and yes, I have a license for it. We use a trap called a dho gazza, which is a small net suspended by two...

Homework Statement Calculate the net torque about the axle of the wheel shown in https://jigsaw.vitalsource.com/books/9781269392464/content/id/ch08fig39 . Assume that a friction torque of 0.40 m · N opposes the motion. Where F=18N (in photo). The picture is here...

On chemwiki, they gave 2 equations to find the standard reduction potential of a cell: Eocell = Eocathode + Eoanode Eocell = Eocathode - Eoanode Why are there 2 equations and when do you use each one? Thanks

Homework Statement The bar, of length AB=2m, with a mass of 6.00 kg. There are two weights, let's call them m1 and m2, hanging off the bar. m1 is 4.4kg, at 0.66m from point A. m2 is 2.0 kg, at 1.84m. The bar is suspended by two spring scales defined as F1 and F2 (assuming negligible mass)...

I am having a lot of difficulty understanding this concept. Suppose you have two objects A,B of mass A',B' connected by a massless rope. Let K Newtons be the force applied on object A .What is now the tension along the rope ? -My reasoning: K Newtons is the force applied to the combination...

Homework Statement Picture related [/B] 1. There is a system of two blocks tied to each other. There is a force F on the small block causing the system to move at a certain acceleration. Find the acceleration. 2. (This is the one I'm not sure about) Instead of force F, we add a pulley with a...

Homework Statement How to prove : [/B] ##P*F_net=((dK)/(dt))## i.e. power associated with the net force is the rate of change of kinetic energy. The Attempt at a Solution [/B] if I use the definition of power ans then that of work I get (m*a*ΔS )*(F_net) further using F_net=ma LHS=...

So we know that an object undergoing horizontal circular motion, has a angular velocity with direction perpendicular to the plane of motion, and also a linear velocity with a direction perpendicular to the acceleration towards the centre of motion Question : if we sum/add the linear+angular...

A discussion from another thread Questions re: Matter-Antimatter Annihilation prompts this question since the discussion there raised the point that a zero net charge seems very unlikely. This new thread's title question might be rephrased as follows: If the universe did have a non-zero charge...

Homework Statement A cylindrical piston shaft weighs 250 g and is held vertically inside an actuator (We can assume actuator is a box with hollow cylindrical space to fit the piston shaft). Compressed air at 100 psi is supplied at the bottom of the actuator and is acting on the piston upwards...

Homework Statement A heat engine operates between a high-temperature reservoir at 634 K and a low-temperature reservoir at 320 K. In one cycle, the engine absorbs 6540 J of heat from the high-temperature reservoir and does 2200 J of work. Homework Equations What is the magnitude of the net...

Homework Statement I have two analog MEMS accelerometers ADXL337, ADXL377. The ADXL337 can measure acceleration upto +/- 3g (where g = gravitational acceleration) and ADXL377 can measure upto acceleration of +/- 200g. More than this much amount of acceleration, would create noise and random...

Homework Statement The 29.5cm diameter disk rotates counterclockwise on an axle through its center. F1=20.8N, F2=58.6N, F3=58.6N, F4=20.8N, and d=5.27cm. What is the net torque about the axle? Let the counterclockwise direction be positive. Homework Equations Torque = force (perpendicular) x...

Homework Statement Imagine you put 10 weights of 100grams on wheels. You attach this "car" to a pulley that hangs over a ledge. You take 1 weight of 100grams off the "car" attach it to the hanging edge of the pulley. The car propels forward what was the acceleration of car and/or net force...

Homework Statement A 0.35 kg particle moves in an xy plane according to x(t) = - 11 + 1 t - 6 t3 and y(t) = 19 + 3 t - 8 t2, with x and y in meters and t in seconds. At t = 0.7 s, what are (a) the magnitude and (b) the angle (within (-180°, 180°] interval relative to the positive direction of...

Homework Statement Assume the magnitude of the electric field on each face of the cube of edge L = 1.07 m in the figure below is uniform and the directions of the fields on each face are as indicated. (Take E1 = 35.1 N/C and E2 = 25.3 N/C.) A.) Find the net electric flux through the cube. B.)...

Homework Statement Consider the figure below, we need to find the charge on Q_0, both charges Q are negative. It is given that the net charge on Q_A is zero. The figure of the problem is attached. The Attempt at a Solution I understand how to get the solution except for one part. I'm just...

Homework Statement [/B] For the situation shown in the diagram, the block of mass m remains in place on the sloping front of the accelerating wedge, even though that sloping front is frictionless. Given these values, M = 20.0 kg, m = 4.00 kg, and theta= 34.0, calculate the net force acting on...

Homework Statement http://www.webassign.net/hrw/W0490-N.jpg The figure above shows three circular arcs centered on the origin of a coordinate system. On each arc, the uniformly distributed charge is given in terms of Q= 2*10-6C. The radii are given in terms of R = 10cm. What is the magnitude...