The position vector r describes the path of an object moving in space. Find the velocity v(t), speed s(t), and acceleration a(t), of the object. r(t) = (et cos(t), et sin(t), et) v(t) = e ( cos(t) - sin(t) ) i te ( sin (t) + cos(t) )j tek X s(t) = V3 et a(t) = [-Ze'sin (t) i + 2e'cos(t) j + ek] X eBook