Question

Time
- 1 = 0
to cover
, 1- 4
loo m
- lớp
4-4​

Answer 1

Answer:

hope this answer useful to you mate

Answer 2

Hii its tom85

we know that

h= ut - gt^2/2

100 = 10t - 5t^2

t^2 - 2t +20= 0

t^2 - 2t + 1+ 19= 0

(t - 1)^2 - (sqrt - 19)^2 = 0

{t - ( sqrt 19 * i +1)}{t - (1 - sqrt 19* i) =0

t= ( sqrt19*i +1) and (1 - sqrt19*i )

where i is called iota = sqrt -1

____________/\__________☺️

hope it may helps you