Convert the given in SI units.
(44 ft/sec)(1 m/ 3.28 ft) = 13.41 m/sec
The distance traveled and the initial velocity can be related through the equation,
d = (Vf)² - (Vi)²/ 2a
where d is the distance, Vf is the final velocity, Vi is the initial velocity, a is the acceleration due to gravity. Substituting the known values from the given above,
d = ((0 m/s)² - (13.41 m/s)²)/ 2(-9.8 m/s²)
The value of d from the equation,
d = 9.17 meters
Convert this to feet,
d = (9.17 m)(3.28 ft / 1 m) = 30 ft
Answer: 30 ft
Answer:

and

Explanation:
See attached figure.
E due to sphere
E due to particule
(1)
according to the law of gauss and superposition Law:
; electric field due to the small sphere with r1=R/4


then:
(2)
on the other hand, for the particule:

⇒
(3)
We replace (2) y (3) in (1):


--------------------
if R<x<2R AND 

remember that 
then:

solving:


but: R<x<2R
so : 
Because the specimen is very small with a light microscope
Answer:
1 hour to ride his motorcycle