The distance the object falls is equal to the height of the building, which is 90 x 3.85 = 346.5 meters.
The acceleration due to gravity can be found using the equation:
d = 1/2 * g * t^2
where d is the distance the object falls, t is the time of fall, and g is the acceleration due to gravity.
Substituting the known values:
346.5 meters = 1/2 * g * (8.50 seconds)^2
Solving for g:
g = 2 * 346.5 meters / (8.50 seconds)^2
g = 9.74 m/s^2
So the acceleration due to gravity on the planet is 9.74 m/s^2.
The impact speed of the object can be found using the equation:
v = g * t
where v is the impact speed and t is the time of fall.
Substituting the known values:
v = 9.74 m/s^2 * 8.50 seconds
v = 82.8 m/s
So, the impact speed of the object is 82.8 m/s.