# Am i doing this problem right? help please

1. Sep 16, 2008

### BeckyStar678

am i doing this problem right? help please!!!

1. The problem statement, all variables and given/known data

a particle initially located at the origin has an acceleration of a=3 j m/s2 and an initial velocity of vi= 5 i m/s. find a.) the vector position and velocity of the particle at any time t and b.) the coordinates and speed of the particle at t=2 s.

2. Relevant equations

3. The attempt at a solution

so for a.) i got the equation xf=0+5(t)+.5(3)(t2) im not really sure where to go from there. it says for any time, so do i just put in any number
to get the velocity i did vf=5+3(t)

for b.) do i just plug in 2 for the times above. im really not sure if im doing this right

2. Sep 16, 2008

### danago

Re: am i doing this problem right? help please!!!

When it says at any time, i think its just saying come up with an equation that gives the displacement for any given value of t, so you would leave t as a variable.

And yea then just plug t=2 into the equations

EDIT: Besides what i missed about the vectors, and tony mentioned below :)

Last edited: Sep 16, 2008
3. Sep 16, 2008

### tony873004

Re: am i doing this problem right? help please!!!

Your answer should have $${\rm{\hat i}}$$ and $${\rm{\hat j}}$$ in them, or your answer is not in vector notation.