Statics

Question 1

How defined the force F?

Answer 1

The force is a vector quantity is defined by: A- Magnitude B- Point of application C- The direction is known.

Question 2

How defined the moment M?

Answer 2

A system of two forces that are equal in magnitude, opposite in direction, and parallel to each other is called a couple.
A moment M is defined as the cross product of the radius vector r and the force F from a point to the line of action of the force.
M = r × F

Question 3

What are equilibrium requirements?

Answer 3

Σ Fn = 0

Σ Mn = 0

Question 4

What is the moment of inertia?

Answer 4

The moment of inertia is the second moment of area, is defined as:
Iy = ∫x2 dA
Ix = ∫y2 dA

Question 5

The polar moment of inertia J of an area about a point?

Answer 5

The polar moment of inertia J of an area about a point is: equal to the sum of the moments of inertia of the area about any two perpendicular axes in the area and passing through the same point.

Question 6

What is Radius of Gyration?

Answer 6

The radius of gyration rp, rx, ry is the distance from a reference axis at which all of the areas can be considered to be concentrated to produce the moment of inertia

Question 7

What is the limiting friction?

Answer 7

It is the largest frictional force where any further increase in applied forces will cause motion.

Question 8

What is the moment of the area?

Answer 8

The first moment of the area with respect to the y-axis and the x-axis, respectively, are:
My = ∫x dA = xc A
Mx = ∫y dA = yc A

Question 9

Normal force ( N ) in friction is:

Answer 9

• The force perpendicular to the surface an object is sliding on.
• The normal force is the force pushing the two surfaces together, and the stronger the normal force, the stronger the force due to friction.