Net Definition and 1000 Threads

Homework Statement well, I'm solving one question from 12U physics, and my answer don't match with others. the question is at attached file. I do not know how to put it in here Fex = 1.35, Fey = 1.35, and Fnet = 1.91 (45°) this one make sense, however on next one, which is "What is...

So, I am having some trouble with understanding force concepts. I do understand that Newton's 3rd law can be described as "describing the same interaction with the same magnitude of force, but in opposite directions on each object." So, I have a concern with a question that I have on my...

1. a 5.0 kg block is pushed up a wall by a 90N force. Assume that the block starts from rest and that it has an acceleration of 0.5m/s^2. a. find the coefficient of kinetic friction between the block and the wall. b. Find the work done by each force acting on the block. c. Find the...

Homework Statement There are 4 charges in the corner of a square with the lengths of the sides measuring 18.2cm q1= 2.34μC (top left) q2=-1.58μC (top right) q3= 2.03μC (bottom left) q4= -3.00μC (bottom right) →Calculate net force on q4 →Calculate net force at the center of the square...

Homework Statement The drawing (not to scale) shows one alignment of the sun, earth, and moon. The gravitational force vector F SM that the sun exerts on the moon is perpendicular to the force vector F EM that the Earth exerts on the moon. The masses are: mass of sun = 1.99 1030 kg, mass of...

Hello everyone, Consider a weight tied to a string spinning in a horizontal circle. According to Newton's third law, the force of the string on the weight (inward) is opposite and equal to the force of the weight on the string (outward). If this is the case, how can there be a net...

Homework Statement Each of the two identical objects carry a net charge. The objects are made of conducting material. One of them is attracted to a positively charged ebonite rod, and the other is repelled by the rod. After the objects are touched together, it is found that they are each...

Homework Statement A large, thin plastic disk with radius R = 1.1 meter carries a uniformly distributed charge of Q = -7e–5 C. A circular piece of aluminum foil is placed d = 3 mm from the disk, parallel to the disk. The foil has a radius of r = 6 cm and a thickness t = 1 millimeter. a...

A 15-g bullet is fired from a rifle. It takes 2.5 × 10^-3 s for the bullet to travel the length of the barrel, and it exits the barrel with a speed of 715 m/s . Assuming that the acceleration of the bullet is constant, find the average net force exerted on the bullet Answer : 4290 N I need...

Homework Statement True or false If an object originally at rest is subjected to more than one non zero force but the forces sum to zero then the particle will not move. Homework Equations None The Attempt at a Solution I say false I think it something to do with angular...

Homework Statement Find the net charge of a system consisting of 2.0×10^7 electrons. Homework Equations e = 1.60 * 10^-19 C The Attempt at a Solution (1.60 * 10^-19) * (2.0×10^7) = 3.2 * 10^-10 ...but I got it incorrect. I'm confused as to how else I'm supposed to solve this.

Question: You’re 1.5 m from a charge distribution whose size is much less than 1 m. You measure an electric field strength of 282 N/C. You move to a distance of 2.0 m, and the field strength becomes 119 N/C. What’s the net charge of the distribution? (Hint: Don’t try to calculate the charge...

Homework Statement Answer: C Note: Sorry admins for the picture, needed to include the diagram though. Homework Equations ∑\tau = I\alpha ∑F = ma a = \alphar The Attempt at a Solution The torques must be balanced (is this reasoning already wrong?), thus, F*R1 = F_T*R2 F_T =...

Homework Statement An elevator that contains three passengers with masses of 72 kg, 84 kg, and 35 kg respectively has a combined mass of 1030 kg. The cable attached to the elevator exerts an upward force of 1.20 x 10^4 N, but friction opposing the motion of the elevator is 1.40 x 10^3 N...

Homework Statement Lets say I have an equilateral triangle, and you are asked to calculate the net force on the top of the triangle Homework Equations Coulombs Law The Attempt at a Solution I know to use Coulombs law to find the forces acting on the top of the triangle, then since...

Homework Statement The question wasn't really written down. It was a question asked after an explanation, and it really wasn't straightforward. I'm going to try to make it into a intelligible thing. If there is a +3 charge and a -1 charge at a distance from one another, where to the right...

Homework Statement Find the net electric field strength at point A due to the combined electric fields of both charges. Homework Equations E=kq/d^2 The Attempt at a Solution I know how to solve these type of problems however I'm just wondering how come in the net force line as you...

Homework Statement Two tugboats are pulling a large log, as shown in the following diagram. The log has a mass of 250 kg and is initially at rest. How far have the tugboats moved the log after 10 s? http://imgur.com/GS7Y80x Homework Equations c^2=a^2 + b^2 -2ab cosC sin A/ a= sin...

Homework Statement The .274 and .88 was found using the equation of electrostatic force . Homework Equations K=q1q2/d^2 The Attempt at a Solution Would I just tan inverse of .274N and .88N which would be 17 degrees. However my question is: how to determine the reference pt: would...

In my book it is written that Newton's shell theorem can be used to show that a uniform shell of matter exerts no net gravitational force on a particle located inside it. How?

A 150 kg motorcycle starts from rest and accelerates at a constant rate along a a distance of 350m. The applied force is 250 N and the coefficient of kinetic friction is 0.03 Find the net force applied to the motorcycle. Find the acceleration of the motorcycle. What is its speed at the...

Homework Statement Which of the following is a correctly written net ionic equation? http://i.minus.com/jYaipNE1rlRic.png Homework Equations Net ionic equation eliminate all spectator ions. The Attempt at a Solution It looks to me as if four of the answer choices are...

Homework Statement Three charges are in a straight row. The first charge has a value of 5.00 x 10-5 C. The second charge also has a value of 5.00 x 10-5 C and is 2.50 cm to the right of the first charge. The third charge has a value of -2.50 x 10-5 C and is 2.00 cm to the right of the...

Homework Statement A sphere of radius ##a## is submerged in a fluid which is flowing in the z-hat direction. There is some associated viscosity in the fluid which will exert a force on the sphere. Use symmetry to argue that the net force will be in the z-direction. Show that it will have the...

Homework Statement An object is made from 2 solid disks: m1 = 23 kg, m2 = 39kg, and r1 = 17cm, and r2 = 33cm. The disks are connected by a thin rod of M = 11kg, L = 67cm. The object is held in a horizontal position and then let go. The object is free to rotate about a pivot through centre of...

Homework Statement The Earth has a mass of 5.98*1024 Kg and the moon has a mass of 7.35*1022 kg. The distance from the centre of the moon to the centre of the Earth is 3.84*108 m. A rocket with a total mass of 1200 kg is 3.0*108 m from the centre of the Earth and directly in between the Earth...

[b]1. A crate is pulled to the right with a force of 82 N, to the left with a force of 115N, upward qith a force of 565N and downward with a force of 236N. [b]2. what is the magnitude and direction of the net external force [b]3. i solved for magnitude(330N) but I am not sure how...

1. A 1000 kg automobile initially moving 72 km/h jams the brakes and skids to a stop in a distance of 24 m on a dry pavement but stops in 81.6 m for a wet pavement. (Neglect reaction delay.) A. Calculate the applied forces for both weather conditions. B. What is the coefficient of friction for...

Homework Statement A 20 kg object is being acted on by a 90 N [E60N] force, a 40 N [S] force, and a 40 N [E27S] force. Find the net force acting on the object and its acceleration. Homework Equations ƩF = ma The Attempt at a Solution I understand that I have to add vector...

Homework Statement In a particular binary star system, Star A has a mass that is 28 times that of Star B. This distance between the stars is 34 AU (astronomical units). Find the location of the point in this star system where the net gravitational force on any mass would be zero. Homework...

I was reading up on net metering, where the electric utility allows one to feed back excess generation by solar panels etc. onto the distribution network. http://en.wikipedia.org/wiki/Net_metering One question I had is, is it fairly easy to match phase for such inverters with the grid...

Homework Statement In the figure below, a uniform beam of length 12.0 m is supported by a horizontal cable and a hinge at angle θ = 40°. The tension in the cable is 600 N. Homework Equations T=F x r The Attempt at a Solution I attempted to calculate the net torque using all the...

Homework Statement A 17m long ladder is mounted on a fire truck. The ladder itself has mass 130kg , and at the top is a 37kg basket holding a 83kg firefighter. If the ladder makes a 60∘ angle with the horizontal, what's the magnitude of the net torque about the ladder's base? Homework...

Homework Statement http://ezto.mhecloud.mcgraw-hill.com/13252699450881445581.tp4?REQUEST=SHOWmedia&media=ch28q44a.jpg A long, straight wire has a 11.1‐A current flowing in the positive x -direction, as shown in the figure. Close to the wire is a square loop of copper wire that carries a...

My textbook says that if you are on a ferris wheel that is rotating, the total work done by all the forces acting on your is zero. How is that possible? You are moving so isn't work being done to you?

Homework Statement Driver brakes 1420kg car moving at 64.8km/h [W]. Car slows down and comes to stop after 729m [w] find net forceHomework Equations a=v/t f=ma The Attempt at a Solution t=40.5 a= 0.44 f=1420(0.44) f= 624.8 My answer is 624.8N TB Answer: 316N what am i doing wrong?

Galaxies radiate energy from their stars, but there is also flows of matter into a galaxy. Is the net energy produced by these flows of matter (evaluated as E=mc^2 under the assumption that it will be processed by stars as nuclear fuel) occurring at a greater or lesser rate than the radiative...

Homework Statement "A 40 kg child sitting 6.0 m from the center of a merry-go-round has a constant speed of 6.0 m/s. The net work (in Joules) done on the child after making one complete circle on the merry-go-round is?"Homework Equations a=V^2/r F=ma C=2pi*r The Attempt at a Solution C ≈...

Homework Statement The three small spheres shown in the figure below carry charges q1 = 4.30 nC, q2 = -7.70 nC, and q3 = 3.40 nC. Find the net electric flux through each of the following closed surfaces shown in cross section in the figure. Homework Equations...

Homework Statement Two point charges q1 = -6.15 nC, and q2 = -10.5 nC are separated by 25.0 cm (see figure below). (a) Find the net electric field these charges produce at point A (b) Find the net electric field these charges produce at point B (c) What would be the magnitude and...

Homework Statement Three point charges have equal magnitudes, two being positive and one negative. These charges are fixed to the corners of an equilateral triangle. The magnitude of each of the charges is 2.9 µC. The lengths of the sides of the triangle are .02m Calculate the magnitude...

For example, if I am given something like HCl and NaOH, or ##HNO_3## and ##Ba(OH)_2##. Can someone explain how I would find the net ionic reaction or provide a link to a good tutorial on how to write the equation for the total/net reaction with only the reagents/reactants?

MgCl2 + Cu(NO3)2 I need the full and net ionic equations for this. I know NO3 is soluble and Cl is soluble too since there's no Ag, Pb, or Hg. Not sure how to write them out though.

Homework Statement I am having a problem with 8.4. I get an answer but it does not match the answer in the memo which I think is wrong. Homework Equations The Attempt at a Solution 8.1) T to P (Could someone explain why?) 8.2) Q = (3*10^-9)-(6*10^-9)/2 = -1.5*10^-9 (This is...

So I am studying mechanical engineering, and I got into a debate with my (mit mechy) graduate roommate about the possibility of having a net nonzero force which involved no actual displacement of an object. Normally, when an object is accelerated along a direction (given an external force)...

Hi, I am very sorry if I have posted in the wrong forum, I don't know wether to post in classical physics or aerospace engineering. I have been wondering this theoretical thing a lot lately and I can't figure it out, it should have a simple straight answer though so your help is very...

Find the Net Resistance between A and B in attachment 1. The circuit in attachment 1 simplifies to attachment 2 from the fact that the points C and E are equipotential. Same goes for D and F. So we remove CE and F as no current passes through equipotential points. But why? How are these 2...

similar to the rough picture of how BHs radiate if I put a proton next to a BH can one of the quarks be absorbed into the BH and the other two escape? I don't really understand confinement very well but does the confinement picture change next to BH horizon?

Homework Statement Homework Equations Net Torque = F1I1 + F2I2The Attempt at a Solution In the y direction, the net force is: 0 = F2-Fg, so F2=Fg. I attempted to do the problem by resolving the net torque, where I defined CW as positive and CCW as negative, so I got: Net Torque = (0.750m)F1...

Homework Statement A 9.0 uF and 4.0 uF capacitors are connected in parallel, and this combination is connected in series with a 12.0 uF capacitor. a) what is the net capacitance? b) if 32 V is applied across the whole network, calculate the voltage across each capacitor. Homework...