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:
When there is nearsightedness or myopia
Explanation:
As, in myopia the image is formed in front of the retina.
Which makes things looking at things near very easy, but looking at far away things very difficult.
So concave lens makes things look bigger, so therefore, it is used during myopia, to make things look bigger when they are far away
Answer:
Explanation:
Of the 4 numbers given, the answer is 1 or A
If you take the absolute value of abs(1 - 1.04) you get 0.04.
(2 - 1.04) = 0.96
1.25 - 1.04 = .21
1.5 - 1.04 = 0.46
The last three are all larger than 0.04
Note: absolute value means the positive difference between 2 numbers (even though it is negative). If it is negative, absolute value makes it positive.
Human lack chlorophyll, which is the function that collects energy from the Sun to conduct photosynthesis.
For conservation of energy we have to:
mgH=mv²/2
Clearing
<span> v=sqrt(2gH)
Then, by definition
</span><span> F=Δp/Δt= Δ(mv)/ Δt=m Δ(v)/Δt=
</span> =m[sqrt(2gH)-0]/Δt= m[sqrt(2gH)]/ Δt
the answer is
F=m[sqrt(2gH)]/ Δt