Answer:
a. Approximately 3.21 seconds
b. Approximately 5.196 m/s
Step-by-step 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