An object is dropped from 20. meters above the moon. The acceleration due to gravity on the moon is 1.62 m/s^2 a. How long does it take for the object to impact the moon?
b. At what speed does it impact the moon?

a. Approximately  3.21 seconds

b. Approximately  5.196 m/s

Explanation:

a. The height from which the object is dropped = 20 meters

The location of the occurrence = The moon

The acceleration due to gravity on the moon  = 1.62 m/s²

The time it took the object to to impact the moon is given by the equation of free fall as follows;

h = 1/2·a·t²

Where;

h =The height from which the object is allowed to freely fall = 20 meters

a = The acceleration due to gravity on the moon  = 1.62 m/s²

t = The time of motion of the object

Substituting the values, gives;

20 = 1/2 × 1.62 × t²

t² = 20/(1.2 × 1.62) ≈ 10.23 s²

t = √ 10.23 ≈ 3.21 s

The time in motion of the object before impact, t = 3.21 seconds

b. The final speed, v is given from the equation for speed under free fall, which is presented as follows;

v = u + a·t

Where

u = The initial vertical velocity = 0

Substituting the values gives;

v = 0 + 1.62 × 3.21 ≈ 5.196 m/s

The final speed, v with which the object impacts the moon ≈ 5.196 m/s

the independent variable, or the one that is intentionally manipulated is the speed.