S(t) = (5-t)(2t-6)+50 = 10t-30-2t²+6t+50 = -2t²+16t+20
V(t) = S'(t) = -4t+16
V(2) = -8+16 = 8 м/с
Eк = mV²/2 = 5•64/2 = 5•32 = 160 Дж
S(t) = (5-t)(2t-6)+50 = 10t-30-2t²+6t+50 = -2t²+16t+20
V(t) = S'(t) = -4t+16
V(2) = -8+16 = 8 м/с
Eк = mV²/2 = 5•64/2 = 5•32 = 160 Дж