just do the usual derivative:
v(t) = z'(t) = -16.2tk
and evaluate at t=3 and t=6
works the same if there are i and j components as well.
A particle's position is given by
z(t) = −(8.10 m/s^2)t^2k
for
t ≥ 0.
(Express your answer in vector form.)
(a) Find the particle's velocity at
t = 3.00 s and t = 6.00 s.
1 answer