# What is Moment forces: Definition and 15 Discussions

Shear and bending moment diagrams are analytical tools used in conjunction with structural analysis to help perform structural design by determining the value of shear force and bending moment at a given point of a structural element such as a beam. These diagrams can be used to easily determine the type, size, and material of a member in a structure so that a given set of loads can be supported without structural failure. Another application of shear and moment diagrams is that the deflection of a beam can be easily determined using either the moment area method or the conjugate beam method.

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1. ### Determine the point of application of a resultant force

I am struggling with part b of the question attached in the screenshot. For part a, I simply add the components of the given forces. I tried calculating the moments using vector cross multiplication, but I don't know what to do after that or even if that step is useful.
2. ### To find the angle between the ground and rods in limiting friction

Could I please ask for help with the following: Here's my diagram: The forces at the hinge (green) are internal forces. For the whole system resolving vertically gives: R1 + R2 = 4W and horizontally gives: F1 = F2 For the rod of weight 3W only, taking moments about B gives: F1 * L *...
3. ### Engineering Statics problem: A ramp is supported by two cables

Problem illustration: The possible answers are: I don't understand why it says Mc if it is asking for the moment at A, not C. But maybe I am getting something wrong. So with the formulas I posted above, I have this:
4. ### Help finding the vertical component of the reaction at C

Hello everyone, For this equation, I have found Ay as 0.677kN by using Ma = 1.5kN(7m)-Ay(15.5m). To find Cy, would I be using the sum of forces to find the answer? For example Fy = Ay - F2 - F1sin55 + Cy = 0 This would then get Cy answer as 2.05kN
5. ### Analyse the cutting force of this bolt cutter

The question is to determine the force in the small opening, delivered from the 250 N on both sides of the plier. i tried multiple things but can't get the answer right. Anyone that could help me? This is my work so far:
6. ### Find the Moment about the ankle

Given that the tibia is 0.6kg and is 35 cm long. The force at the knee (Fk) is: (-200i + 346.41j)N Find the moment about the ankle due to Fk I found that: r: rx = (0.35cos60) and ry = (0.35sin60) Using the sum of moments where: rxFy - ryFx = 0 [(0.35cos60)(346.41)] - [(0.35sin60)(-200)] =...
7. ### Solving a Homework Problem with One Pivot

Homework Statement https://cdn.discordapp.com/attachments/373928512811302912/528638926148337704/question.PNG part a )50N I cannot answer part b. Homework Equations M=FD The Attempt at a Solution Ok so if both pivots were in contact with the beam I would just equate them with the oppposite...
8. ### Equilibrium of a stiff plate on inclined planes

Homework Statement A thin stiff uniform rectangular plate with width L (L =AB) is lying on two inclined surface as shown in Fig. 3-1. The angle between the horizontal surface and the left inclined surface is α, and that between the horizontal surface and the right inclined surface is β. It is...
9. G

### How can I find the torque/moment of force about an axis?

Homework Statement The Trump's wall is so weak that has to be supported by two cables as is shown in the figure. If the tension over the cables BD and FE are 900 N and 675 N respectively. (I'LL UPLOAD AN IMAGE OF THE PROBLEM SO YOU CAN SEE IT) Homework Equations τ = r χ F Mo = r χ F The...
10. ### Solving Torque and Moment Problems: Why Can't We Use Center of Mass as Pivot?

Homework Statement Regarding part (c) (i), as we know that we can consider any of the convenient point as our pivot. If I consider the point where the 5kg mass (center of mass of the bag) acts, the asnwer turns out to be wrong. The correct answer has 4kg mass as pivot Homework Equations...
11. ### Force on wheels in an accelerating vehicle

Assume that a motorcycle of mass m has two wheels that are equidistant from its centre i.e the force on each wheel is m*g/2. If the motorcycle accelerates forward, will the two forces on each wheel (measured instantaneously) remain the same? If not, how can one mathematically describe the...
12. ### Resulting force using moment?

I just can't figure this out with the stresses and moments. What is the force required on the handle to get the 850N on top? Link to album: goo.gl/FYpc0k
13. ### Rotational force of motor + potential gear reduction

I'm trying to determine how powerful of a stepper motor I need for a project. I am attempting to take a display that weighs 15lbs and transition it from laying flat to inclined (approximately 45 degrees) using a stepper motor. I had considered a linear actuator since it would have been an easier...
14. ### Statics - Moment using both vector and scalar approaches

Homework Statement Homework Equations Mo=Fd Mo=r x F The Attempt at a Solution Alright guys, I did the whole process but I'm pretty sure I just made a little bump somewhere in my calculations which screwed up my answers. First I found everything I could find OA = 350j, so the unit vector...
15. ### Direction of moment forces

Homework Statement How do u find whether the moment is negative or positive in the three examples shown?? Even if you use the right hand rule, for case 2 i have seen that the moment is negative and not positive. I am taking counter clockwise as positive moments. Please help out. Thanks...