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Vanyuwa [196]
3 years ago
8

An example of an exothermic reaction is:

Physics
1 answer:
elena55 [62]3 years ago
6 0

Answer:

C.

Explanation:

Exothermic refers to a RELEASE of energy through a reaction(usually chemical). When salt dissociates, polar water molecules pull apart ions, releasing energy.

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The origin of an x axis is placed at the center of a nonconducting solid sphere of radius R that carries a charge +qsphere distr
MA_775_DIABLO [31]

Answer:

q=49Q/64

and

x =16R/15

Explanation:

See  attached figure.

E_{Q}= E due to sphere

E_{q}= E due to particule

E_{total}=E_{Q}-E_{q}=0  (1)

according to the law of gauss and superposition Law:

E_{Q}=E_{1}+E_{2}=E_{2} ; electric field due to the small sphere with r1=R/4

E_{Q}=kq_{2}/(r_{1}^{2})=

q_{2}=density*4/3*pi*r_{1}^{3}=Q/(4/3*pi*R^{3})*4/3*pi*r_{1}^{3}=Q*r_{1}^{3}/R^{3}

then: E_{Q}=kq_{2}/(r_{1}^{2})=k*Q*r_{1}^{3}/(R^{3}*r_{1}^{2}) = kQ/(4*R^{2})  (2)

on the other hand, for the particule:

E_{q}=kq/(r_{p}^{2})

r_{p}=2R-R/4=7R/4   ⇒    E_{q}=16kq/(49R^{2})   (3)

We replace (2) y (3) in (1):

E_{total}=E_{Q}-E_{q}=0=kQ/(4*R^{2}) - 49kq/(16R^{2})

q=49Q/64

--------------------

if R<x<2R   AND E_{total}=E_{Q}-E_{q}=0

E_{total}=E_{Q}-E_{q}=0=kQ/(x^{2}) - kq/(2R-x^{2})

remember that  q=49Q/64

then:

Q(2R-x^{2})=49/64*x^{2}

solving:

x_{1} =16R/15

x_{2} =16R

but: R<x<2R  

so : x =16R/15

7 0
3 years ago
When the cornea and lens of the eye do not properly focus
frutty [35]

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

3 0
3 years ago
Hello, I wanted an answer from a mathematician. The number 1.04 is closer to the number 1, 2, 1.25 or 1.5.
babymother [125]

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.

3 0
2 years ago
Humans cannot convert the Sun's energy into glucose for themselves because humans lack _____.
rosijanka [135]
Human lack chlorophyll, which is the function that collects energy from the Sun to conduct photosynthesis.
3 0
2 years ago
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A hammer of mass m falls from rest off of a roof and drops a height H onto your head.
belka [17]
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
 
6 0
3 years ago
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