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3 years ago

What is the definition of the science of human development?

1 answer:

7 0

<span>Human development refers to the biological and psychological development of thehuman being throughout the lifespan. It consists of the development from infancy, childhood, and adolescence to adulthood. The scientific study of psychologicalhuman development is sometimes known as Developmental psychology. Hope this helps.</span>

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How are n type semiconductors and p type semiconductors alike. How are they different

Virty [35]

<span>N-type semiconductor materials have been with elements which have spare electrons in their outer shells. This gives N-type silicon free electrons (which are negatively charged partials) which can move about at will - with the potential to create current.

P-type semiconductor materials have been in the opposite way, with elements that have too few electrons in their outer shells. Therefore the opposite of electrons - holes - are free to move about within the material - with the potential to create current.

You can think of it like positive and negative poles of a magnet.

When you place a piece of N-type silicon next to a piece of P-type silicon, they form a diode. The excess electrons in the N-type are attracted to the excess holes in the P-type, forming what is known as a P-N junction. If you then put a potential difference (voltage) across the junction such that the P-type is sufficiently higher potential than the N-type, electrons will be able to jump across the boarder from the N-type to the P-type, creating current in the opposite direction.
If you apply the potential difference in the opposite direction, such that the N-type is at a higher potential than the P-type, there is no flow of electrons from the P to the N-type because the N-type already has too many. There is no current flow.
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8 0

4 years ago

Two wires of the same material and having the same volume, are fixed

Setler79 [48]

Answer:

48 kg

Explanation:

Given that the two wires are of same material, so their value of young's modulus will be same

Assuming that the wires are cylindrical in shape

As radius of the first wire is half that of the second wire and therefore the area of cross-section of the first wire will be one-fourth of the second wire( ∵ wire is cylindrical, the cross-sectional part will be circle and the area of the circle = π × r² )

As the volume is same for both wires

∴ π × ( $r_{1}$ )² × $l_{1}$ = π × ( $r_{2}$ )² × $l_{2}$

Here

$r_{1}$ is the radius of the first wire

$r_{2}$ is the radius of the second wire

$l_{1}$ is the length of the first wire

$l_{2}$ is the length of the second wire

⇒ π × (( $r_{2}$ )² ÷ 4) × $l_{1}$ = π × ( $r_{2}$ )² × $l_{2}$ (∵ radius of first wire is half that of the second wire)

By cancelling the same terms on both sides

we get

$l_{1}$ = 4 × $l_{2}$

⇒ Length of first wire will be four times of the length of second wire

<h3>Strain is defined as the elongation per unit length</h3>

Strain in first wire = ΔL ÷ $l_{1}$ = ΔL ÷ (4 × $l_{2}$ )

where ΔL is the elongation of the wire which in this case is same in both wires

Strain in second wire = ΔL ÷ $l_{2}$

∴ Strain in second wire is four times of strain in first wire

<h3>Stress = F ÷ A</h3>

where F is the force perpendicular to the cross-sectional area

A is the area of cross-section

Force in first wire = $m_{1}$ × g

where $m_{1}$ is the mass hanged to the first wire

g is the acceleration due to gravity

Force in second wire = $m_{2}$ × g

where $m_{2}$ is the mass hanged to the second wire

g is the acceleration due to gravity

Let $A_{1}$ be the cross-sectional area of first wire

$A_{2}$ be the cross-sectional area of second wire

$A_{2}$ = 4 × $A_{1}$ (∵ cross=sectional area of the wire = π × (radius of the wire)² )

Stress in first wire = ( $m_{1}$ × g) ÷ ( $A_{1}$ )

Stress in second wire = ( $m_{2}$ × g) ÷ ( $A_{2}$ ) = ( $m_{2}$ × g) ÷ (4 × $A_{1}$ )

<h3>Young's modulus is defined as Stress per unit strain</h3>

As Young's modulus is same for both wires, Stress per unit strain must be same for both wires

Stress per unit strain of first wire = (( $m_{1}$ × g) ÷ ( $A_{1}$ )) ÷ (ΔL ÷ (4 × $l_{2}$ ))

Stress per unit strain of second wire = (( $m_{2}$ × g) ÷ (4 × $A_{1}$ )) ÷ (ΔL ÷ $l_{2}$ )

By equating them we get

$m_{2}$ = 16 × $m_{1}$

⇒ $m_{2}$ = 16 × 3 = 48 kg

∴ $m_{2}$ = 48 kg

5 0

3 years ago

An artist wants to create a metal sculpture using a mold so that his artwork can be readily mass produced. He wants his sculptur

lukranit [14]

Answer:NO

Explanation:

No the mold should not be of the same size as that of sculpture because the material from which molds is made may shrink or expand depending upon its properties .

For example grey cast iron shrinks on cooling.

We need to make mold bigger in general so that if there is a need of finishing it can be done easily without altering the size of sculpture.

5 0

3 years ago

A block with a mass of 6.0 kg is

Umnica [9.8K]

(a) The normal force on the block is 50.92 N.

(b) The horizontal force on block keeping it in equilibrium is 29.4 N.

The given parameters;