What is Resultant force: Definition and 172 Discussions

In physics and engineering, a resultant force is the single force and associated torque obtained by combining a system of forces and torques acting on a rigid body. The defining feature of a resultant force, or resultant force-torque, is that it has the same effect on the rigid body as the original system of forces. Calculating and visualizing the resultant force on a body is done through computational analysis, or (in the case of sufficiently simple systems) a free body diagram.
The point of application of the resultant force determines its associated torque. The term resultant force should be understood to refer to both the forces and torques acting on a rigid body, which is why some use the term ' resultant force-torque.

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  1. G

    Direction of resultant force from a point

    Homework Statement I managed to get Fy = 900N , Fx = 200N and FR= 922N , how to get the distance from A is 3.56m ? tetha= arc tan (922/200) = 77.5 degree Homework EquationsThe Attempt at a Solution
  2. R

    Resultant force on pipe (Fluid Mechanics)

    Homework Statement Posted in picture below Homework Equations Bernoulli's Equation P/pg + v1^2/2g + z1 = P/pg + v2^2/pg + z2 The Attempt at a Solution Posted in picture below Wasn't sure if what I did was correct...still practising the topic itself
  3. G

    Resultant Force - Find Fx,Fy & Ans of 52.8N

    1. The problem statement, all variables and given/known dat the ans given is 52.8N . I tried to let Fx and F y =0. for Fx , I have 120-20(12/13) -170(8/17)=21.5N (to the right) for Fy , I have 90-170(15/17) = -60N( in upwards direction ) but my ans is incorrect = 63.7 N ( by using resultant...
  4. G

    Using Right Hand Thumb Rule to Determine Resultant Force

    the moment is r X F = rFsin tetha which means r is projected to F , am i right . If so , then the resultant force should point downwards( by using right hand thumb rule) , am i right?
  5. 0

    Finding resultant force on a segment of submerged wall

    Please see the attached image. I understand the area represents the resultant force per unit width. But I'm unsure what equation to come up with for the purple area. I'd appreciate a little patience here, it's been ages since I did this. Thanks
  6. A

    Resultant effect of number forces acting simultaneously

    Hello Friends, I want to discuss about methods to find resultant force for number of forces acting simultaneously on a body in same plane have a look at this http://www.scienceinfusion.com/force-and-composition-of-forces/'][/PLAIN]...
  7. G

    Centripetal force is resultant force?

    Homework Statement I know that centripetal is the resultant force acting to enable the a body to move in a circular path ... But , in the triangle , the R3 looks like the resultant force ..Can someone tell me which is the correct resultant force in this diagram ? What is R3 actually ...
  8. P

    Question on velocity changes in free fall

    Homework Statement Assume a ping pong of mass 3g is falling, and it has fallen 1m and is now traveling at 5 m/s. If the air resistance force is half its weight, how far will it travel in the next 0.1 seconds. [Hint: you may want to sketch a velocity-time graph) Homework Equations Understanding...
  9. K

    Resultant force acting on axial compressor

    Hello, I've got one problem with fluid flow reaction force which acts on compressor. I hope you can help me with that. Here is a sketch to my question: I wonder in which direction resultant force will be directed. I understand that air is flowing from left to right with inlet velocity V1...
  10. B

    Need help with mechanics statics; finding resultant force

    Hi! Can anyone help me with these problems? When I try to draw a parallelogram, I couldn't find the angles. Please help. http://imageshack.com/a/img673/8733/GsXt9f.jpg http://imageshack.com/a/img910/1949/1AB7iB.jpg
  11. H

    Resultant Force of two vectors

    Find the result force of the two forces. This problem seemed easy at first, but I think I'm confused as to how to find the coordinate angle (gamma) . For the ( i,j,k) components of F1, I got (300cos(30)i, 0j, 300sin(30)k) I don't understand the function of the 45 degree angle, either. What am...
  12. I

    Line of action for which the resultant force of the wrench passes

    In tightening a bolt whose center is at point O, a person exerts a 180-N force on the ratchet handle with his right hand. In addition, with his left hand he exerts a 90-N force as shown in order to secure the socket onto the bolt head. Determine the equivalent force–couple system at O. Then find...
  13. B

    Calculating Resultant Force of F3 in 3D Space

    Homework Statement If the coordinate direction angles for F3 = 650lb are α = 110∘, β = 25∘ and γ = 76∘, determine the magnitude of the resultant force acting on the eyebolt. FIGURE: Homework Equations ? The Attempt at a Solution ? New semester, and so happy to start with a...
  14. K

    Resultant force on the piston at the end of stroke

    Homework Statement my question is on part a , the ans is 4260N . but my answer is double of the ans given. why I'm wrong? the working is shown in the photo. Homework Equations The Attempt at a Solution
  15. A

    Resultant force when a body is accelerating

    Homework Statement There is a body of mass 500kg accelerating at 2.5ms^-2. It experiences a frictional force of 1000N. Homework Equations Resultant Force = ma The Attempt at a Solution Resultant Force = (500)(2.5)N = 1250N The body is moving forward with a net force of 1250N A...
  16. F

    Point of application of resultant force from bound vector forces

    Hello Forum, in the case of two or multiple free vectors, it is easy to determine graphically (head-tail rule) the resultant vector (magnitude and direction). The resultant vector is also a free vector. A free vector is actually an infinite number of vectors with the same magnitude and...
  17. B

    How to reduce a distributed load to a resultant force

    Hi everyone, So I am trying to study how different types of slurry will deflect a PVC pipe. The first step in my understanding is to reduce distributed load into a resultant force. I'm assuming that the resultant force will be placed in the center of the pipe (assuming a homogeneous...
  18. C

    Can anyone check my working on the resultant force ,test question

    Homework Statement http://i1345.photobucket.com/albums/p679/Duk_Bato/Untitled_zps268ea812.png http://i1345.photobucket.com/albums/p679/Duk_Bato/Untitled_zpsbae78257.png Homework Equations ƩMA = Ʃ r x F Total Force of x,y= 0 The Attempt at a Solution bi)150(0.4)+(50)(0.3)-Fsin50(0.5) =0...
  19. S

    3D Vectors and resultant force

    Homework Statement The vertices of a quadrilateral are A(1,2,-1) B(-3,2,-3) C(4,1,-4) and D(2,-1,3). At A forces of magnitude 4, 5 and 4 are Newtons act along AB, AC, and AD respectively. Find the resultant force. Looking for more of a hint than an answer. Any help would be...
  20. J

    Resultant Force: Calculating Forces with Trigonometry for a 800N and 600N Object

    I'm sure this problem is pretty trivial to most but apologies in advance, I'm just starting out sorry. Homework Statement I'm not sure how to go about working this out due to the 800N The Attempt at a Solution F1 (800N) x-pos = 800 tan (90)?? , y-pos = ? F2 (600N) x-pos...
  21. M

    Sprinter resultant force question

    Question: Just after the gun a sprinter of mass 65kg is pushing against the starting block with a force of 800N. The force acts at an angle of 65 degrees to the horizontal. Calculate: - the resultant horizontal force acting on her - the resultant vertical force acting on her - the...
  22. A

    Replace all the loads on the beam with one resultant force.

    Homework Statement Knowing the distance d=1.5m, determine the resultant of the loads acting on the beam shown in the attachment. Specify the point of application of this resultant on the beam. Given data: F1=100KN, l1=1m. F2=50kN,l2=1.5m. F3=60KN, l3=4m. Variables: Resultant Force R, and its...
  23. STEMucator

    Resultant Force #2 - Calculating ##\vec{F}_R##

    Homework Statement I need to calculate the resultant force ##\vec{F}_R## for the following : http://gyazo.com/5f2d7aad6aaed178135909480016e04a I had another thread where I clarified a few things I hope will be good now. Homework Equations The Attempt at a Solution So first...
  24. STEMucator

    How Do You Calculate the Resultant Force Between Two Vectors?

    Homework Statement Given ##\vec{F}_1 = 22N [N]##, ##\vec{F}_2 = 38N [E 35° S]##, and the angle between them is 125° calculate ##\vec{F}_R##. Picture : http://gyazo.com/a95dc91a95639edc7f1ef21f469976d1 Homework Equations N for Newtons. The Attempt at a Solution I used ##\vec{F}_R =...
  25. C

    Statics: Find resultant force and couple moment

    http://imageshack.us/a/img842/2497/112639506.jpg Calculate the resultant force’s magnitude and the couple moment. Let a = 3.70 m w1=5.35kN/m w2=4.00kN/m The resultant force of the triangle is 1/2(3.70)(5.35)=9.898 kN The resultant force of the rectangle is (4)(3.70) = 14.8kN So...
  26. C

    Statics Question: Finding resultant force and orientation

    Determine the magnitude of the resultant force FR. Assume that F1 = 230 and F2 = 395 Express your answer to three significant figures and include the appropriate units. Determine the direction of the resultant force FR , measured counterclockwise from the positive x axis. I got the...
  27. C

    Finding the Resultant Force of Two Attached Bars

    Homework Statement http://img6.imageshack.us/img6/4041/meprob210.jpg This was a plate with two bars attached / coming out of it (A and B, represented by Fa and Fb, respectively). The question says: Determine the angle of θ for connecting member A to the plate so that the resultant...
  28. C

    Resolved resultant force along a specific axis

    Homework Statement http://img687.imageshack.us/img687/8767/meprob27.jpg If the resultant force acts along the positive u axis, determine the resultant force and angle theta (red angle) Homework Equations law of sines pythagorean theorem, etc trig parallelogram, head to tail methods...
  29. A

    Resultant force on a pulley system

    Homework Statement Could anyone give me an idea of how to start this problem to work out the resultant force's magnitude, direction and couple in the top (alternator) pulley? Does the 30° angle affect the equations? As all the notes I have seem to only have pulleys with the force at each...
  30. 9

    Question regarding the elevator acceleration resultant force

    Question regarding the "elevator" acceleration resultant force Homework Statement In the "elevator" case, when a man is standing on a weighing scale, and the elevator accelerate upwards, the resultant force acting on the man will be UPWARD force, and the man is feeling "HEAVIER". So here is...
  31. M

    Resultant Force on an object during Non-Uniform Motion

    Homework Statement A 0.30-kg mass attached to the end of a string swings in a vertical circle (R = 1.6 m), as shown. At an instant when θ = 50°, the tension in the string is 8.0 N. What is the magnitude of the resultant force on the mass at this instant...
  32. N

    Determine x and y coordinates of resultant force through object

    Homework Statement The concrete slab supports the six vertical loads shown. Determine the x- and y-coordinates of the point on the slab through with the resultant of the loading system passes. Image attached Homework Equations The Attempt at a Solution I started off by...
  33. A

    Calculating resultant force of friction from rope and bar.

    Hello, I hope this is a suitable forum, it's a million miles from homework but it may be on the same sort of level. A picture is worth a thousand words so please have a look at the attached picture. When the rope is pulled there isn't just the issue of gravity, but also of the friction of...
  34. E

    Calculating the Resultant Force on a Gate - Is No Force at B Possible?

    I've figured out the resultant force on the gate by adding the magnitudes of F1, F2, and F3. However, I'm trying to figure out the distance b such that there is absolutely no force acting on the stop at point B. Is this even possible? It seems like it isn't, since all forces are pointing to the...
  35. N

    Force Couple System and resultant force

    Homework Statement Replace the force-couple system at point O by a single force. Specify the coordinate yA of the point on the y-axis through which the line of action of this resultant force passes. Homework Equations The Attempt at a Solution I'm not sure how to start this...
  36. C

    Statics: Determine the magnitude of the resultant force

    [b]1. Homework Statement : The Attempt at a Solution I keep attempting this problem and so far I have got this: F1x: 150 F1y:260 F2x:424 F2y:424 F3x:600 F3y:250 Then I add the x's together and y's together, square both and take the square root for magnitude, but can't seem...
  37. C

    Resultant force from three forces.

    Homework Statement http://session.masteringengineering.com/problemAsset/1127110/6/Probs.2-39_40.jpg I will refer to this picture for the problem. I have to find the resultant of the three force vectors. I know all except F1 and theta. I am given it for this problem to find the resultant...
  38. U

    Resultant force projected along a line

    Homework Statement (i) Find the resultant force acting at point D and write it in Cartesian form. (Note that CD is parallel to the y-axis, the 40N force acts parallel to the z-axis and the 30N force is parallel to the x-axis.) (ii) Find the magnitude of the projected component of the...
  39. A

    Finding the resultant force on the block

    Homework Statement Hi all, I've been given a question for homework and I am not 100% sure how to do it exactly! I have included a diagram or the situation Homework Equations The question is Find the resultant force on the block (picture attached) The Attempt at a Solution What i did...
  40. J

    5-point star resultant force question

    Any help on where I start with this question. Need to convert each force into its horizontal and vertical components, but don't know any angles apart from the 70N force acting straight down.
  41. B

    Components of A Resultant Force

    The following problem is one I have contrived by my own ability, so if there is any error please let me know. Say I have a box, with a chain attached at one of the edges of the box, and I apply 10 N pull at a 40° angle with the surface of the box. Now I know we sometimes resolve vectors into...
  42. R

    Finding the Angle of Resultant Force in a Plane

    Homework Statement I am having quite an issue solving this resultant force question: The following forces act on a point in the same plane: 40N direction due north; 10N direction due east, 40N direction 50° south of west, 20N direction northwest and 15N direction 20° south of east...
  43. S

    Calculation of % component of resultant force

    Hi everyone, This appears to be a trivial question but I'm uncertain to the correct answer. If I have forces of 3N, 4N and 5N in the x,y and z directions respectively. The resultant force will be the square root of these components squared ≈ 7N. If I want to describe any of the components...
  44. N

    Moments and the line of action of the resultant force

    Homework Statement Homework Equations ƩMoments = Moment + Fx*d + Fy*d R = (Fx)i + (Fy)j The Attempt at a Solution I'm only interested in part (ii) I calculated the components of the resultant force and they are |R| = 1.15(i) + 9.36(j) I know that the x-intercept of line of action...
  45. P

    Find Resultant Force of F1,3 & F2,3 | .899 N Magnitude

    I need to find the resultant force for two separate forces - F1,3 and F2,3. F1,3's components are x= -.719 and y= -.54. F2,3's components are x= .719 and y= -.54. The angle between the q1-q3 line and the x-axis is 36.9. F1,3 and F2,3's magnitude is .899 N. Can someone help me?
  46. M

    How do I find the tension and angles in a spider's web?

    Homework Statement A spider is resting after starting to spin its web. The gravitational force on the spider is 0.165 N on the junction of three strands of silk. The junction is supported by different tension forces in the two strands above it so that the resultant force on the junction...
  47. A

    What is the resultant force acting on a skydiver in free fall?

    Hi guys, please help me with this problem. thanks A 75 kg sky-diver in free fall is subjected to a crosswind exerting a force of 60 Newton and to a vertical air resistance force of 100 Newton. Describe the resultant force acting on the skydiver. I used the formula to calculate the resultant...
  48. nukeman

    Resultant Force: Something I am messing up on in calculation - ?

    Resultant Force: Something I am messing up on in calculation - ? Homework Statement Hey all, This is a resultant force word problem. I will just post the my answer and the problems answer. I have no idea why there is a different answer here. Correct: R^2=1500^2+2300^2 - 2 x 1500 x...
  49. S

    Resultant Force of Two Applied Forces on a Car

    Two forces, 489 N at 11 ◦ and 444 N at 25 ◦ are applied to a car in an effort to accelerate it What is the magnitude of the resultant of these two forces? Answer in units of N.
  50. S

    Calculating Resultant Force of 2 Fluids in a Tank

    1. A tank with vertical walls, 2m wide and 2m long and 2.5m high, is filled with 4800 litres of water (density 1000 kg/m3) and 3200 litres of light oil (density 900 kg/m3). Calculate the magnitude and location of the resultant force on each of the vertical walls of the tank. 2. By doing some...
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