Given:
initial velocity (u) = 21 m/s
time (t) = 8 seconds
acceleration (a) = 9 m/s²
distance (s) = ????????
Now,
you can use the formula, [tex]s=ut+ \frac{1}{2} a t^{2} [/tex]
Now, plug the values in the formula, and you get:
[tex]s=21*8+ \frac{1}{2} *9 * 8^{2} [/tex]
[tex]s=21*8+ \frac{1}{2} *9 * 64[/tex]
[tex]s=21*8+ \frac{1}{2} *576[/tex]
[tex]s=21*8+ 288[/tex]
[tex]s=168+288[/tex]
[tex]s= 456~meters[/tex]
SO THE INITIAL HEIGHT OF THE ROCK WAS 456 METERS.
