Question

A body is dropped from a height of 80 m it reaches to earths surface in

Answer 1

hey mate

here is your answer

given:
h=80 m
u=0
t=?

assumption: g=10 m/s²

h=ut+1/2gt²

80=0*t+1/2*10*t²

80=5*t²

t²=80/5

t²=16

t=±4

but t≠ -4

hence t=4 s (answer)