quote:Original post by Aj37
List all that apply. As a projectile moves through its parabolic trajectory, which of these quantities, if any can take the value "0" at least at some point during the passage.
A. horizontal component of velocity
B. vertical component of velocity
C. Speed
D. horizontal component of acceleration
E. Vertical component of acceleration

The correct answers are B and D. but I do not understand why. Can someone briefly explain?

It''s pretty simple. ''A'', ''E'' are all constant while a projectile is in motion, and while it moving it''s speed (C) > zero. That leaves ''B'' and ''D''. In parabolic motion ''D'' is always zero, and ''B'' is zero when a projectile is a the apex of it''s arc.

I hope that''s all clear (and right =)).

-- Zhypoh!

I''m closing this thread and several others because the question appears to be a school homework assignment from a math class. The purpose of homework is to teach students to build their comprehension of a subject and their problem-solving skills, possibly with the assistance of other students in the same class or teachers of the class. Especially for math problems such as the one posed here, it is absolutely NOT appropriate to seek the answers from folks outside one''s class or school.

These forums are to be used for assistance in game development activities only.

Graham Rhodes
Senior Scientist
Applied Research Associates, Inc.