E.Mech - Statics of rigid bodies

What is a free body diagram (FBD)?

• A graphical representation of a rigid body

• A diagram showing all forces and moments acting on a body

• A 3D model of the body

• A diagram showing only the external forces on a body

Which of the following is a type of support that prevents rotation and movement in all directions?

• Roller support

• Hinge support

• Fixed support

• Simple support

Varignon's theorem states that:

• The sum of all moments about a point is zero

• The moment of a force about a point is equal to the sum of the moments of its components about the same point

• The moment of a couple is equal to the sum of the forces in the couple

• The moment of a force about an axis is equal to its perpendicular distance

What is a couple in mechanics?

• Two forces acting in opposite directions at different points

• Two parallel forces equal in magnitude and opposite in direction

• Two forces acting at an angle to each other

• A single force causing a moment

Which of the following conditions must be satisfied for a rigid body to be in equilibrium in two dimensions?

• ΣFx=0

• ΣFy=0

• ΣMz=0

• All of the above

The scalar component of a moment is calculated by:

• Multiplying the force and perpendicular distance

• Adding the force components

• Subtracting the force components

• Dividing the force by the distance

The moment of a force about an axis can be expressed as:

• M=r⋅F

• M=r×F

• M=F⋅r

• M=F×r

Which of the following is true for a rigid body in stable equilibrium?

• The body remains in its new position when displaced slightly

• The body returns to its original position when displaced slightly

• The body moves further away from its original position when displaced slightly

• None of the above

The equivalent force system of a body is represented as:

• A single force and a single couple

• Two equal forces

• A single force and multiple moments

• A set of perpendicular forces

The reaction force at a roller support is:

• Always horizontal

• Always vertical

• Perpendicular to the inclined surface

• Tangential to the surface