⚛️ Physics · Motion in a Plane · NEET & JEE

Two particles are simultaneously projected from same point: one horizontally at v, other vertically at v. Time for their velocity vectors to become perpendicular is (g=10):

Answer: v/g.

A v/g
B v/(2g)
C 2v/g
D v/g - some time

Correct answer: A. v/g

Explanation: v1=(v, -gt), v2=(0, v-gt). For perpendicular: v1·v2=0 → 0 + (-gt)(v-gt)=0 → t=v/g.

Projectile trajectories launched at 15, 30, 45, 60, 75 and 90 degrees at the same speed, each annotated with range R, maximum height H and time of flight T, with coloured dots marking equal time intervals

Projectiles at equal speed: range is maximum at 45°, and complementary angles (30° and 60°) share the same range. Image: Cmglee, CC BY-SA 3.0, via Wikimedia Commons.

Concept context

Vectors, projectile motion, uniform circular motion, and relative velocity - the foundation of 2D kinematics for NEET and JEE.

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Two particles are simultaneously projected from same point: one horizontally at v, other vertically at v. Time for their velocity vectors to become perpendicular is (g=10):

Concept context

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