# Projectiles with unequal initial velocities, purely horizontal

If projectiles $$A$$ and $$B$$ are projected horizontally with different initial velocity from the same height, then both $$A$$ and $$B$$ possess the same vertical component of velocity, at any instant.

Since the initial velocity is in the horizontal direction, the vertical component at this instant is 0. However, as the particles start falling towards the ground, they get accelerated towards the ground(due to g), and since they have different initial velocities, I cannot understand why their vertical component must be the same.

• "possess the same vertical component of velocity" when? Initially, or always. acceleration is independent of the material content of the projectile so no matter what, neglecting air resistance, the vertical motion will be the same. But your question is too vague and requires a lot of assuming. – ggcg May 13 at 12:07
• It is always. I changed it. – Chrys May 13 at 12:11
• I'll provide an answer. – ggcg May 13 at 12:13
• Voting to close. Kindly elaborate why you think they should be different or what do you find wrong/confusing about the argument that proves that they would be the same. Welcome to Physics SE! :) – Feynmans Out for Grumpy Cat May 13 at 12:30
• Did the editing. – Chrys May 13 at 12:34