Question

solved answer just need help understanding.
A helicopter is to fly directly from a helipad at the origin in the direction of the point (1,1,1) at a speed of 60ft/sec. What is the position of the helicopter after 10 sec?

u= (1/sqrt(3) I + 1/sqrt(3) j +1/sqrt(3) k -- got this from the unit vector

r(t)= r0 + t(speed)u

0=t(60) ( (1/sqrt(3) I + 1/sqrt(3) j +1/sqrt(3) k) ----understand this part

=20sqrt(3)t(I + j + K) ------How did we get this??