Question

consider following equation of motion & rewrite them as free fall body
1) v=u+at
2)s=ut+1/2at×at

Answer 1

in a free fall the initial velocity becomes zero and acceleration becomes acceleration due to gravity
v=u+at
v=0+gt
v=gt

s=ut+1/2at×t
h=0×t+1/2gt×t
h=1/2gt2

Answer 2

Free Fall:
A body is said to be free fall when only gravitational force acts on that body.

General equations of motion:
1. V=u+at
2.S=ut+1/2at²
3. V²-u²=2as

Important Points to Remember:
-->When a body is falling vertically downwards its velocity increases.
So g=+g =+9.8m/s²

--->For a free fall object:
initial velocity =u=0;
equation of motion will change as
V=0+gt ⇒v=gt
∴t=time descent=v/g=u/g[∵time of ascent= time of descent]
t=u/g ----------(1)

Second equation of motion:
h=0+1/2gt²
h=1/2gt² ----------(2)

third equation of motion:
As the object reaches ground its final velocity will be zero:
So V=0;
0²-u²=2gh
u=√2gh-----(3)