NEET Momentum Conservation MCQs & PYQs

Total mechanical energy \(E = K + U\) can be negative if potential energy \(U\) is negative and larger in magnitude than kinetic energy \(K\).

However, kinetic energy \(K = \frac{1}{2}mv^2\) is always non-negative, implying momentum exists. The magnitude of linear momentum \(|\vec{p}| = mv\) is always non-negative.

Therefore, both Assertion and Reason are false.

Assertion (A) is false; as objects move towards each other due to mutual attraction, their potential energy decreases, and kinetic energy increases, so it does not remain constant.

Reason (R) is false; total linear momentum of a system is conserved only in the absence of external forces, not 'even in the presence of external forces'. Therefore, both (A) and (R) are false.