An external force is always required to break the inertia of a body which is either in the state of rest or state of uniform motion. Which law governs this statement?

An external force is always required to brake the inertia of a body which is either in the state of rest or state of uniform motion. Can all forces produce acceleration? Why?

An external force is always required to brake the inertia of a body which is either in the state of rest or state of uniform motion. A boy holding a spring balance in his hand suspend a mass 2kg from it. If the balance slips from his hand and falls down, find the reading of the balance while it is in the air.

Elasticity is the property of a body by which it regains its original state on the removal of the deforming force. Why Steel is more elastic than Rubber?

State the law which governs the working of a generator

Consider moment of inertia of a uniform thin circular disc about a diametrical axis of the disc. There is a theorem which helps to find the moment of inertia of the disc about another axis parallel to this axis. Give the statement of this theorem.