Answer:

Explanation:
The elastic potential energy of a spring is given by
, where
is the spring constant of the spring and
is displacement from point of equilibrium.
When released, this potential energy will be converted into kinetic energy. Kinetic energy is given by
, where
is the mass of the object and
is the object's velocity.
Thus, we have:

Substituting given values, we get:

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 : 
Answer:
1.03 m/s
Explanation:
I'm too lazy to write the explanation down but my teacher graded this and it was right
Answer:
Phenomenon
Explanation:
phe·nom·e·non
/fəˈnäməˌnän/
noun
1.
a fact or situation that is observed to exist or happen, especially one whose cause or explanation is in question:
"glaciers are unique and interesting natural phenomena"
synonyms
occurrence, event, happening, fact, situation, etc.
2.
a remarkable person, thing, or event:
"the band was a pop phenomenon just for their sales figures alone"
synonyms
marvel, sensation, wonder, prodigy, miracle, etc.