Photons are also known as beta particles. (true or false)

Which statement is true regarding flexibility? A. joint's range of motion cannot be maintained with age. b.A joint's range of mo

Alex777 [14]

<span>the statement that is true regarding flexibility is : b. a joint's range of motion will be lost if the joint is not used regularly. Our body is like a machine. If we not constantly heat it up, our body will be more prone to injury. We can see that the old people who lived within the tribe in the middle of the mountain are far stronger than the one who lived in the city.</span>

3 0

2 years ago

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You pull on a spring whose spring constant is 22 N/m, and stretch it from its equilibrium length of 0.3 m to a length of 0.7 m.

Liono4ka [1.6K]

Answer:

W= 4.4 J

Explanation

Elastic potential energy theory

If we have a spring of constant K to which a force F that produces a Δx deformation is applied, we apply Hooke's law:

F=K*x Formula (1): The force F applied to the spring is proportional to the deformation x of the spring.

As the force is variable to calculate the work we define an average force

$F_{a} =\frac{F_{f}+F_{i} }{2}$ Formula (2)

Ff: final force

Fi: initial force

The work done on the spring is :

W = Fa*Δx

Fa : average force

Δx : displacement

$W = F_{a} (x_{f} -x_{i} )$ :Formula (3)

$x_{f}$ : final deformation

$x_{i}$ :initial deformation

Problem development

We calculate Ff and Fi , applying formula (1) :

$F_{f} = K*x_{f} =22\frac{N}{m} *0.7m =15.4N$

$F_{i} = K*x_{i} =22\frac{N}{m} *0.3m =6.6N$

We calculate average force applying formula (2):

$F_{a} =\frac{15.4N+6.2N}{2} = 11 N$

We calculate the work done on the spring applying formula (3) : :

W= 11N*(0.7m-0.3m) = 11N*0.4m=4.4 N*m = 4.4 Joule = 4.4 J

Work done in stages

Work is the change of elastic potential energy (ΔEp)

W=ΔEp

ΔEp= Epf-Epi

Epf= final potential energy

Epi=initial potential energy

$E_{pf} =\frac{1}{2} *k*x_{f}^{2}$

$E_{pi} =\frac{1}{2} *k*x_{i}^{2}$

$E_{pf} =\frac{1}{2} *22*0.7^{2} = 5.39 J$

$E_{pf} =\frac{1}{2} *22*0.3^{2} = 0.99 J$

W=ΔEp= 5.39 J-0.99 J = 4.4J

:

4 0

2 years ago

1.

charle [14.2K]

Answer:

i love devon bostick

Explanation:

cause....... i do

8 0

3 years ago

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What is the density of a block of marble that

EleoNora [17]

Explanation:

Solution,

Volume (v)=287 cm^3

Mass(m)=816 g

Density(d)=m/v

=816/287

=2.84

So, the density of the block of marbles is 2.84 g/cm^3.

I hope it helped U

stay safe stay happy

5 0

2 years ago

Why is the ionic compound magnesium chloride neutral

shutvik [7]

Answer: The charges on cation and anion balances each other.

Explanation:

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

$Mg:12:1s^22s^22p^63s^2$

$Mg^{2+}:10:1s^22s^22p^6$

$Cl:17:1s^22s^22p^63s^23p^5$

$Cl^{-}:18:1s^22s^22p^63s^23p^6$

Thus $Mg^{2+}$ combines with two $Cl^-$ ions to give neutral $MgCl_2$

8 0

3 years ago