Assertion (A) The angle between acceleration and velocity of a body is one-dimensional motion is always zero…
Assertion (A) The angle between acceleration and velocity of a body is one-dimensional motion is always zero. Reason (R) One-dimensional motion is along a straight line.
Both (A) and (R) are true and (R) is the correct explanation of (A).
Both (A) and (R) are true but (R) is not the correct explanation of (A).
(A) is true but (R) is false.
(A) is false but (R) is true.
Solution
Assertion is incorrect as during decceleration, i.e. when body is slowing down, acceleration and velocity are directed opposite to each other. Hence, angle between $\mathbf{a}$ and $\mathbf{v}$ may be $180^{\circ}$ or $0^{\circ}$. Reason is correct.