Question

d=2.1 a=? vi=0 and t=.60 and i have to use the formula d=vit+1/2at^2, how do i do this? can you please show work so i can understand.

Answer 1

actually

x = Xi + Vi t + (1/2) a t^2
where
x = position
Xi = initial position
Vi = initial speed
a = acceleration
t = time
here
2.1 = 0 + 0 (.6) +(1/2) a (.6)^2
2.1 = (1/2)(.36) a
a = 4.2/.36

Answer 2

2.1=0(.6)+.5(a)(.6^2)

you can get drop the vit since vi=0. that will leave you with
2.1=.5a.6^2
multiply (.5)6^2 then you can divide 2.1 with the answer you got.