What is Net torque: Definition and 93 Discussions

Net force is the vector sum of forces acting on a particle or body. The net force is a single force that replaces the effect of the original forces on the particle's motion. It gives the particle the same acceleration as all those actual forces together as described by Newton's second law of motion.
In physics, it is possible to determine the torque associated with the point of application of a net force so that it maintains the movement of jets of the object under the original system of forces. Its associated torque, the net force, becomes the resultant force and has the same effect on the rotational motion of the object as all actual forces taken together. It is possible for a system of forces to define a torque-free resultant force. In this case, the net force, when applied at the proper line of action, has the same effect on the body as all of the forces at their points of application. It is not always possible to find a torque-free resultant force.

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  1. MichaelKD

    Net Torque Within a Mass and Pulley System

    I started by summing the forces and torques to get: - ma = mg-T - I*alpha=Tr I then used a=alpha*r and I=Mr^2 to combine the equations and solved for angular acceleration equals 81.75rad/s^2. Plugging this back into a torque equation I got that the net torque is 1.04Nm. However, the problem...
  2. paulimerci

    Three equal forces applied to a rectangle, find net torque direction?

    This is how I interpreted the problem, a) The net torque about point A is zero. This is because the forces F1 and F2 are equal and opposite, and they act at the same distance from point A. Therefore, they produce torques that cancel each other out.. The force F3 doesn’t does not produce any...
  3. paulimerci

    Net torque about an axis through point A in a massless rod

    The net torque about an axis through point A is given by, If I take the axis of rotation perpendicular to the paper and the solution I arrive would be the following below Net torque = 30 cos45 x 1.5 - 10 cos30X 3 = 5.829Nm ( counterclockwise) But the book gives an answer...
  4. paulimerci

    Determine the net torque acting about the center of mass

    Net torque = 2gx20xcos30 - 2gx35xcos20 - 2gx15xcos60 + 2gx30xcos80 = -357Nm Have I done it right?
  5. D

    Effect on net torque and net force on spools

    I think both spools will land about at the spot x (there aren't any horizontal forces causing them to land away from the x). Also, I think student 2 might be the closest to being correct, but I'm not sure if they're entirely correct; isn't it possible that force doesn't only go to translational...
  6. guyvsdcsniper

    Why is Fty positive in the Σtorque equation?

    I am reviewing this problem from my textbook and am having some trouble with it. When solving for ΣTorque I chose the hinge to be the axis of rotation. I understand that from this point if the board is being held up and it were to fall after removing support, mg (the center of mass of the board)...
  7. Isabel1747

    Rotational Inertia and Net Torque with Friction

    I converted the amount of rotations completed in 5 seconds into radians. 23.4 rot * 2pi = 147 rad I found the angular acceleration of the object in the first 5 seconds it was speeding up. Wf = Wi + at a = 5.881 rad/s^2 I then used the moment of inertia given in the problem to solve for torque. T...
  8. D

    What angles produce a net torque of 1250 Nm on an angled arm?

    Homework Statement My teacher gave us a solution of + 1250 Nm Where CCW = positive torque I know that the torque of the 600N + 300N forces + 1250Nm = the torque of the 500N force. I can't figure out what angles work with the forces at the end of the pipe. Homework Equations Σ T = 1250 Nm T...
  9. C

    Calculating Net Torque in a Rotating System

    Homework Statement hi my question is that say if rod of length l is 3m and is 90 degrees from horizontal pointing upwards with 2 kg weight on the end then there will be no torque produced because the force of gravity is acting parallel to the lever arm if the angle theta is 80 degrees then the...
  10. R

    Tension and net torque in a cable

    Homework Statement In figure 12-34, a uniform beam of weight 500N and length 3m is suspended horizontally, on the left it is hinged to the wall and on the right end of the beam is a cable attached to support it. the cable is attached distance D up the wall from the hinge. The least amount of...
  11. Krushnaraj Pandya

    How is net torque zero about hinge of rod in ball rod system

    Homework Statement There are 2 situations- 1)a rod of length L is lying on a smooth horizontal surface with its one end hinged to the ground, a ball traveling with a velocity v hits its other end and comes to rest, How is the net external torque about hinge point O zero? 2) in the second case...
  12. Andres Padilla

    Find the mass M so that the net torque is zero

    Homework Statement Hello, I have a problem I don't want how to approach, it is a little weird. It is a problem of equilibrium (torque) The situation and my approach is in the picture I uploaded. A beam is supported by the blue structure. On the beam it is a person(100N) at a distance of 3m in...
  13. Pushoam

    Virtual work = 0 implies net torque = 0

    Homework Statement Homework Equations ## \vec \tau = \Sigma \vec r_i \times \vec F_i ## The Attempt at a Solution ## \vec \tau = \Sigma \vec r_i \times \vec F_i ## ## \delta W = \Sigma F_i \delta x_i ## Let's take our Cartesian coordinate system such that the axis of rotation...
  14. F

    Where to place a weight on a bar so that the net torque is 0

    Homework Statement A 0.100-kg, 59.9-cm-long uniform bar has a small 0.055-kg mass glued to its left end and a small 0.100-kgmass glued to the other end. You want to balance this system horizontally on a fulcrum placed just under its center of gravity. no diagram given Homework Equations Στ = 0...
  15. S

    Rigid Object Under net torque question

    Homework Statement An electric motor turns a flywheel through a drive belt that joins a pulley n the motor and a pulley that is rigidly attached to the flywheel. The flywheel is a solid disk with a mass of 80.0kg and a radius R = 0.625m. It turns on a frictionless axle. Its pulley has much...
  16. Erenjaeger

    Calculating Net Torque for an Inclined Wheel: A Problem in Applied Physics

    Homework Statement Find the net torque on the wheel in the figure below about the axle through O, taking a = 13.0 cm and b = 31.0 cm. (Assume that the positive direction is counterclockwise.) pic...
  17. P

    Proving that net torque isn't reliant on point of rotation.

    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...
  18. heartshapedbox

    Describe the angular momentum of the ball and net torque on

    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...
  19. J

    Calculating Net Torque on Wheel Axle

    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...
  20. V

    Torque required to rotate 5 flywheels connected with 1 belt

    Hi, I have 5 machines with flywheels, which are connected with one single belt, so that all five flywheels rotate together. Torque required for each flywheel to rotate is 300 Nm and rpm is 500. what would be the total torque required to rotate five flywheels connected with one belt?
  21. K

    Finding the net torque about the axle?

    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...
  22. minimario

    Solving for Net Torque: W = Torque * Distance

    Homework Statement Homework Equations W = Torque * distance 3. The Attempt at a Solution The net torque is 8*.09-11*.06 = .06, and the distance moved is 4pi, because 2 full rotations, but this is not one of the choices...
  23. T

    Calculating net torque on a plate

    Homework Statement I'm supposed to be finding the net torque on a square plate. The sides are 1.7 m in length, with a force acting on each corner (30 N top left pointed right, 60 N top right pointed down, 20 N bottom left pointed up, and 40 N bottom right at an angle of 37 degrees). Just for...
  24. K

    Finding mass of a meter stick using torque

    Homework Statement I did a lab and am trying to find the mass of a meter stick. Our fulcrum was at the 60cm mark at the meter stick. A 100 g mass was placed 30 cm away from the fulcrum on the shorter side. A 50 g mass was placed 43 cm away from the fulcrum on the longer side. How do I find the...
  25. J

    Net Torque of 2 Forces: Calculate for 59.9N, 28.3cm, 29.6°

    Homework Statement Two 59.9N forces are applied in opposite directions to the 28.3cm long figure shown. If the angle θ = 29.6°, what is the net torque about the center of mass...
  26. W

    Calculate the net torque using all the forces

    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...
  27. N

    Net Torque: Determine Magnitude from Ladder Base

    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...
  28. N

    Question: How do I account for the wire below the loop when finding net torque?

    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...
  29. A

    How to Solve for F1 in a Net Torque Problem?

    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...
  30. B

    Net torque, electric dipole confusion

    Hello all, I am so confused on why a net torque on a dipole in a uniform electric field would not be equal to zero. Wouldn't one end rotate clockwise, the other counterclockwise and cancel out to zero? Thanks.
  31. I

    Finding magnitude and direction of net torque on a dipole

    Homework Statement For the dipole shown, the charges are ± 3.0 micro coulombs separated by a distance of 3.20 nm and oriented so that the theta is 35.0 degrees. If the electric field has a magnitude of 8000 N/C, find the magnitude and direction (clockwise/counterclockwise) of the net torque...
  32. N

    Net torque question? Block 1 and block 2 hanging on pulley?

    In Fig. 10.45, block 1 has mass m1=460g, block 2 has mass m2=500g, and the pulley, which is mounted on a horizontal axle with negligible friction ahs radius R=5.0cm. When released from rest, block 2 falls 75.0cm in 5.00 s without the cord slipping on the pulley. (e) What is its rotational...
  33. S

    Why is the net torque not exactly zero.

    Homework Statement The sum of the net torques is zero even f the numerical result is not. Rather than simply explaining that the net torque is close to zero, justify that your net torque is small, within the context of this experiment. 2. Attached is a pdf of the lab that we had this...
  34. P

    HW Lab PHYS101: Net torque of pulley system and meterstick position balance

    THANKS, I ONLY NEED HELP #2 NOW, PLEASE 10/31/12 @ 9:10 pm bumpHomework Statement 1)If the fulcrum of a 0.1 kg meter stick was placed at the 40 cm mark and a 200 g mass at the 0 cm mark, would it be possible to balance the meter stick with a 200 g mass on the long side of the meter stick? What...
  35. P

    Dipole moment and net torque of an atom

    Homework Statement The HCl (hydrochloric acid) molecule has a dipole moment of about 3.4x10-30 C.m. The two atoms are separated by about 1.10-10 m. What is the net charge on each atom? What is maximal torque that this dipole will experience in a 5.104 N/C electric field? How much energy one...
  36. O

    How does a net torque of 0 make a board snap?

    This is just a scenario I have been pondering. Imagine one took a board and placed it on a pivot in perfect equilibrium. Next they added two 10KG weights 1 inch out, on each side of the pivot. The board would probably not snap with the weights at this distance, but let's say one were to...
  37. J

    What happens when net torque is zero?

    I know that net torque is the sum of torques in a given situation. So take this as an example: If I used a wrench to turn a nut counterclockwise and it succesfully moves, is the net torque going to be non-zero? If so, then can someone please give me an example where the net torque can be zero...
  38. A

    Why doesnt net torque cause angular velocity to increase upto infinity?

    If i have a shaft & I'm applying a driving torque D at one end & at other end there is resisting torque R due to bearing friction, etc. Then if D>R, i have net torque = moment of inertia times angular acceleration. Since the ang. accln is constant with respect to time, will the ang. speed of...
  39. nukeman

    Metronome question: Figuring out net torque and expression for beats per minute?

    Homework Statement A metronome is a device used by musicians to help them adjust the timing of their music to a standard number of beats per minute. The position of the moveable slider determines the frequency. It is possible to build a simple mechanical metronome using a light stick...
  40. M

    Finding the angular acceleration knowing the net torque

    Homework Statement So I worked out a problem where a uniform disk with 3 forces being applied. I found the correct net torque acting on the disk. Now the problem is asking me to find the angular acceleration. Homework Equations r= I*(ang.acc^)2 The Attempt at a Solution I made...
  41. D

    Finding the Net Torque of a Circular Object

    Homework Statement A circular-shaped object of mass 9 kg has an inner radius of 7 cm and an outer radius of 20 cm. Three forces (acting perpendicular to the axis of rotation) of magnitudes 12 N, 27 N, and 16 N act on the object, as shown. The force of magnitude 27 N acts 29 below the...
  42. C

    Net Torque: Calculating Momentum & Time

    is there any formula of net torque? as we know, net force = momentum / time right? what about net torque?
  43. E

    Net Torque / Rotational Dynamics Pulley System help

    Homework Statement A uniform, solid cylinder with mass M and radius 2R rests on a horizontal tabletop. A string is attached by a yoke to a frictionless axle through the center of the cylinder so that the cylinder can rotate about the axle. The string runs over a disk-shaped pulley with mass M...
  44. S

    Net Torque and Conservation of Angular Momentum

    G'day all, I have been reading that if there are no external torques on a system, then angular momentum will be conserved. Can a system be defined as anything or only a single rigid object. Could I define the "system" as 2 disks rotating side by side? If so then the total angular momentum of...
  45. DocZaius

    Problem with zero net torque using a particular axis.

    I was looking at a situation where a fridge in the back of a truck is just about to tip back due to the truck's acceleration. I am looking at the moment just before it tips. The net torque here is 0 since it is not yet tipping back. I thought I was allowed to pick any axis I wished and so picked...
  46. J

    Simple concept help: Pulley and Net Torque

    Homework Statement A ball (hollow sphere) of radius .11m and mass .444kg is mounted on a frictionless axle. A massless cord is wrapped around the ball supporting an object of mass .02kg. Find the angular acceleration of the wheel, linear acceleration of the object and tension in the cord...
  47. T

    What is the net torque given the angles of applied forces

    1. STATEMENT Calculate the net torque about a fixed pointfor 2 different forces given the angles of the applied forces. 2. MY QUESTION what is the net force, meaning how do i fint it? and what do i do wit the information given? Do i use T=r x F...
  48. T

    Solving for Net Torque on Uniform Mass Density Rod

    Homework Statement A rod has a uniform mass density of 0.05 kg/cm it has a moment of inertia equal to 0.1ML^2. The rod sweeps out an area equal to 0.25* pi meters squared in 4 seconds. If you apply a net torque of -1/16 Nm to the rotating rod, how many revolutions will the rod make before...
  49. M

    Rigid object under net torque: 2 blocks, pulley, on incline

    Homework Statement A block with mass m1=2.00kg is on a flat surface and a block of mass m2=6.00kg is on an incline and they are connected by a massless string over a pulley in the shape of a solid disk with a radius R=0.250m and mass M=10.0kg. The angle of the incline is \Theta=30o and the...
  50. V

    Net torque Problem in gear system

    If I have a gear system that consist of 2 gears that are meshed together the first has 16 teeth which is the driver and the 2nd has 36 teeths which is the follower, power transmitted by the driver equal to 5 kw and the driver is rotating at 30 rps and has a known diameter, the usual way to...