At time t, in hours, a lake is covered with ice of thickness y cm, where y = 0.4t^1.4

1) How fast is the ice forming when t = 1? When t = 2? Given units

When t =1

When t =2

2) If ice forms for 0 < t < 3, at what time in this interval is the ice thickest? At what time is the ice forming fastest? Give units

Ice is thickest at t =

Ice is forming fastest at t =

Please send steps because I'm so confused on this one.