Recent content by a_helal

Thank you . . . PF is Great work well done

Hello , I'm Ahmed from Egypt Alexandria 21 years old and study mathematics and programming I'm Undergraduate thanks for this site and i hope to get help to understand some things in my study as i love to understand not face to face but through keyboard and writing not oral or talks. happy day...

ok thanks i understood

if i have no velocity in one direction then there is no acceleration ? i deal with acceleration for sphere in fluid so i use spherical polar co ordinates (ρ,θ,Φ) i have no velocity in Φ then there is no acceleration in Φ direction ? i want to be sure