Answer:
176.58 m/s
Step-by-step explanation:
assume that the acceleration due to gravity, g = 9.81 m/s²
I also assume we neglect air resistance (hence we assume no terminal velocity)
recall that one of the equations of motions can be expressed as
v = u + at, where
u = initial velocity = 0 (because it says you started from rest)
v = final velocity (we are asked to find this)
a = acceleration due to gravity = 9.81 m/s²
t = time = given as 18s
simply substitute the above into the equation.
v = 0 + (9.81)(18)
v = 176.58 m/s