Question

1 a Fyn b с d To explain theorectical concept Explain law of transmissibility of forces Explain the Varignon's theorem List down unkown forces from various types of support Differentiate between centroid moment of inertia and moment of inertia about an axis

Answer 1

(a) law of transmissibility of forces: • The principle of transmissibility states that the point of application of a force can be moved anywhere along its line of action without changing the external reaction forces on a rigid body. And, if a force acts at any point on the rigid body it may also be considered to act at any other point on its line of motion. (b) Varignon's theorem: • The theorem states that the torque of a resultant of two concurrent forces about any point is equal to the algebraic sum of the torques of its components about the same point. "If many concurrent forces are acting on a body, then the algebraic sum of torques of all the forces about a point in the plane of the forces is equal to the torque of their resultant about the same point. (c) unknown forces from various type of support: • Pinned Support it resists horizontal and vertical forces but not a moment • Roller Support • Roller supports can resist a vertical force but not a horizontal force • simple support- • restrain vertical forces but not horizontal forces (d) Difference between centroid moment of inertia and moment of inertia about an axis: • The moment of inertia of an area with respect to any given axis is equal to the moment of inertia with respect to the centroidal axis plus the product of the area and the square of the distance between the 2 axis. Moment of inertia is defined with respect to a specific rotation axis. The moment of inertia of a point mass with respect to an axis is defined as the product of the mass times the distance from the axis squared.