Assuming no friction form air, how far will a dropped rock fall in 10 seconds

Given that

time (t) = 10 s,

(S) = ?

We know that S = ut + 1/2 a. t² m

since free fall and no air friction,

a = g = 9.81 m/s²; initial velocity u = 0

S = 0 + [1/2 * 9.81 * 10²]

S = 490.5 m