Question

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 force exerted by the Earth and net upward force exerted on the body are not equal to each other. A) Only (i) and (ii) B) Only (ii) and (iii) C) Only (i) and (iii) D) All (i), (ii) and (iii)

Answer 1

B

Step-by-step explanation:

The correct statement is:

B) Only (ii) and (iii)

Step-by-step explanation:

(i) An object will continue moving uniformly until the resultant force on it is zero. This statement is not entirely true. An object will continue moving uniformly (at a constant velocity) if the net force acting on it is zero. It doesn't have to be at rest for this condition to apply.

(ii) The bodies do not change their state of rest or motion unless acted upon by an unbalanced external force. This statement is a fundamental principle of Newton's first law of motion, often referred to as the law of inertia. It is true that objects tend to maintain their state of rest or motion unless an unbalanced external force acts on them.

(iii) If a body is at rest on the surface of the Earth, then the net downward force exerted by the Earth and net upward force exerted on the body are not equal to each other. This statement is also true. When an object is at rest on the Earth's surface, the gravitational force pulling it downward (its weight) is balanced by the normal force exerted by the surface upward. These two forces are equal in magnitude and opposite in direction, resulting in a net force of zero.

So, option B is the correct choice because it includes the two true statements (ii) and (iii).