A : Due to inertia an object is unable to change by itself its state of rest and uniform motion.
R : An object cannot change its state unless acted upon by an unbalanced external force.

Assertion : Inertia is the property by virtue of which the body is unable to change by itself the state of rest only. Reason : The bodies do not change their state unless acted upon by an unbalanced external force.

…...cause a change in the state of an object at rest or in uniform motion.

Name the property of bodies (or objects) to resist a change in their state of rest or of motion.

Which of the following statements are true? (i) An object will continue moving uniformly until the resultant force on it is zero. (ii) The bodies do not change their state of rest or motion unless acted upon by an unbalanced external force. (iii) If a body is at rest on the surface of the Earth, then the net downward Torce exer force exerted by the Earth and net upward force exerted on the body are not equal to each other.