Statics of body in two dimensions

In summary, the conversation is about solving a physics problem involving a 50 lb force being applied to a corner plate. The goal is to determine an equivalent system consisting of a 150 lb force at B and another force at A. There is an algebraic solution to the problem, but the person is wondering if it can be solved using a table of moments and forces. The conversation also discusses finding the direction of forces and the lack of available help for the course.
  • #1
togo
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Homework Statement



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Homework Equations



A 50 lb force is applied to a corner plate as shown. Determine an equivalent system consisting of a 150 lb force at B and another force at A.

The Attempt at a Solution



There is an algebraic solution to the problem, but I was wondering if it was possible to solve this problem using a table of moments and forces?

the Fx = 25 lb and Fy = 43.3 lb.

Thanks
 
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  • #2
First write down what you know.

We have a force at B and a force at A with components,

Bx, By, Ax, Ay.

We know the magnitude of B is √(Bx^2 + By^2) = 150 lbs.

We are given a force F = Fx i + Fy j

You know Fx = Ax + Bx and Fy = Ay + By

And we can take moments about points A and B (and at the point where F acts) to get two (three) more equations.

Its just a lot of algebra after that?
 
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  • #3
a table like this:

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if course it wouldn't be measured in kips, it would be measured in lbs.
 
  • #4
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Let's abandon the table idea. Can someone explain to me why, in the solution to this problem, (part b) they say "Having found the direction of the forces P and P', we complete the solution..."

when as you can see in the photo, there is no indication of the direction of the force P', although P was solved for. (the solution seems to come after this sentence which confuses me). Thanks.

2qv6uzm.jpg


this is the missing information. Please help; there are no tutors available for this course, the teacher isn't available, and its getting extremely hard to find help.
 
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  • #5
for your question! I would like to point out that the use of tables of moments and forces is a common and effective approach to solving problems in statics. However, in this particular problem, it may not be the most efficient method.

To solve this problem using a table of moments and forces, we would first need to construct a free-body diagram and then apply the equations of equilibrium (sum of forces and sum of moments) to find the unknown forces at points A and B. This process can be time-consuming and may require multiple iterations to arrive at the correct solution.

On the other hand, the algebraic approach involves using basic trigonometry and vector addition to find the magnitudes and directions of the unknown forces at A and B. This method is often faster and more straightforward.

In conclusion, while it is possible to solve this problem using a table of moments and forces, the algebraic approach may be more efficient in this case. However, it is always beneficial to have multiple problem-solving techniques in your toolkit as different problems may require different approaches.
 

FAQ: Statics of body in two dimensions

1. What is the difference between statics and dynamics in the study of the body in two dimensions?

Statics is the study of bodies at rest or in equilibrium, while dynamics is the study of bodies in motion. In the context of two-dimensional bodies, statics focuses on the forces acting on a body and how they balance out, while dynamics looks at how these forces cause the body to move and change its position.

2. How do you determine the equilibrium of a body in two dimensions?

To determine the equilibrium of a body in two dimensions, you must first draw a free-body diagram that shows all the external forces acting on the body. Then, using the principles of Newton's laws of motion, you can analyze the forces and determine if they are in balance. If the forces are in balance, the body is in equilibrium.

3. What are the three types of equilibrium in the study of two-dimensional bodies?

The three types of equilibrium are stable, unstable, and neutral. In stable equilibrium, a small displacement from the equilibrium position will cause the body to return to its original position. In unstable equilibrium, a small displacement will cause the body to move away from its original position. In neutral equilibrium, a small displacement will not cause any change in the body's position.

4. How do you calculate the moment of a force in two-dimensional statics?

The moment of a force is the measure of its tendency to cause a body to rotate about a specific point or axis. To calculate the moment of a force in two-dimensional statics, you can use the equation M = F * d, where M is the moment, F is the magnitude of the force, and d is the perpendicular distance from the point/axis of rotation to the line of action of the force.

5. Can you apply the principles of statics to real-life situations?

Yes, the principles of statics can be applied to real-life situations, such as engineering and architecture. By understanding the forces acting on a structure or object, engineers and architects can design and build structures that are stable and safe. This also applies to everyday objects, such as furniture and vehicles, which must be designed to withstand different forces and remain in equilibrium.

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