Projectile Motion?

[azn_dj]

Hey how do you derive the equations for projectile motion in vector form?
Thanks, all

[tazza]

Start off with acc(t) = -9.8j, and then go from there (anti deriving to get velocity and position, whilst using initial conditions.

[costa94]

a = -gj
v = -gtj + v(0)
r = -1/2gt^2j + v(0)t + r(0)

[azn_dj]

I understand in the J direction, but what about the i direction?

[azn_dj]

Oh wait hang on a second, I think I have answered my own question
V(0) will be xcos(theta) i + x sin(theta) j
Thanks anyways

[costa94]

i velocity is always constant unless there is air resistance, but spec rarely says that otherwise it tells you 'resistance blergh' (not in projectile motion though...)
j comp. is just affected by gravity

[azn_dj]

Just had to jog my memory, that's all. Thanks everyone