v(t) = x'(t) = -1/12 * 3*t² + 2t - 5 = -t²/4 + 2t - 5
a(t) = v'(t) = -1/4 * 2t + 2 = -t/2 + 2
-t/2 + 2 = 0
-t/2 = -2
t = 4 c
ответ: 4 с
v(t) = x'(t) = -1/12 * 3*t² + 2t - 5 = -t²/4 + 2t - 5
a(t) = v'(t) = -1/4 * 2t + 2 = -t/2 + 2
-t/2 + 2 = 0
-t/2 = -2
t = 4 c
ответ: 4 с