With position vector
[tex]\vec r(t)=(t+1)\,\vec\imath+(t^2-1)\,\vec\jmath+2t\,vec k[/tex]
the particle then has velocity
[tex]\vec v(t)=\dfrac{\mathrm d\vec r(t)}{\mathrm dt}=\vec\imath+2t\,\vec\jmath+2\,vec k[/tex]
and acceleration
[tex]\vec a(t)=\dfrac{\mathrm d\vec v(t)}{\mathrm dt}=\dfrac{\mathrm d^2\vec r(t)}{\mathrm dt^2}=2\,\vec\jmath[/tex]
Then [tex]t=1[/tex], then particle's velocity and acceleration are, respectively,
[tex]\vec v=\vec\imath+2\vec\jmath+2\,\vec k[/tex]
and
[tex]\vec a=2\,\vec\jmath[/tex]
