Assertion ; In projectile motion, the angle between instantaneous velocity vector and acceleration vector can be anything between 0 to ( ) (excluding the limiting case.) Reason : In projectile motion, acceleration vector is always pointing vertically downwards. (Neglect air friction).

Step-by-step solution

Both the Assertion and the Reason are correct, and the reason is the correct explanation of the assertion. The Reason is true because, neglecting air friction, the only force on a projectile is gravity, which causes a constant downward acceleration. The Assertion is true because the velocity vector's direction constantly changes, while the acceleration vector remains fixed. This causes the angle between them to continuously vary from a large angle (obtuse) on the way up to a small angle (acute) on the way down, pas