Resposta :
s= 4 -5t +3t³
a) s(1)= 4-5.1+3.1³
s(1)= 4-5+3
s(1)= 2
s(3)= 4-5.3+3.3³
s(3)= 4-15+81
s(3)= 70
V= d/t
V= 70 - 2/ 3-1
V= 68/2
V= 31 m/s
b) s(1)= 2
V= d/t
V= 2/1
V= 2m/s
s(3)= 70
V= d/t
V= 70/3
V= 23,3 m/s
c) a= v/t
a= d/t/t
a= d/t²
s(0)= 4
s(2)= 4-10+24= 18
a= 18-4/ 2²
a= 14/4
a= 3,5 m/s²