Show all necessary work in the space provided in a neat and orderly fashion. Use
ID: 1867900 • Letter: S
Question
Show all necessary work in the space provided in a neat and orderly fashion. Use good drawing technique and complete free-body diagrams. State necessary observations and assumptions. The problems are weighted as shown. The exam has six pages Part A: Short Answer Problems (5 points each) 1. An ob eet is in static equilibrium if ?F-0 and ? M = 0. What do you know about the velocity of an object that is in static equilibrium? 2. Free-body diagrams are used to help solve static equilibrium problems. What important information can be displayed in a free-body diagram? (List at least three different but general types of information). 2 3. A two-force member (ie., a "link") supports force only along the longitudinal axis of the member. List two conditions that must exist in order to produce a two-force member 4. Friction force, F, can be calculated by F N, where u is the friction coefficient and N is the normal force, but only when either of two conditions exist. What are these two conditions? 5. The principle of transmissibility is often very helpful when solving equilibrium problems. What does this principle allow you to do? Page 1 of 6Explanation / Answer
(1)- the condition for static equilibrium means that the system has zero velocity and the net force acting on it is zero.
(2)- A free body diagram is an important step to visualise all the forces acting on it.
The direction of the arrow shows the direction of forces acting on the member. Each force arrow is labelled to indicate the exact type of force.
The FBD of a system helps us to identify the forces, motions, directions, through which we can figure out component of forces in 3 spatial axes, and help us to write net force equation.
(3)- if an element has pins or hinge supports at both ends and carries no load in between, then it is known as two force member.
These two forces must be equal in magnitude, co-linear and opposite in sense.
The line of action of the resultant force must pass along the centre line of the element.
(5)- as per the principle of transmitibility, we can move the point of application of the force anywhere along it's line of action without changing the external reaction force.