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2 years ago

How do you derive the drift velocity equation (I = nAve)?

1 answer:

4 0

Current is just number of electrons (times its charge) passing by in a given time (in seconds for amps). say you have a volume filled with moving electrons (ignore the inner shell electrons since they stay put) if this volume is constantly moving, the current is just the total charge of this moving volume divided by the total time it takes to pass a certain surface. total charge is e*n*A*L where l is the length (this is just total volume*charge density*charge/electron) the time it takes this to move a distance L is the time for all the charges to move across some 'measuring' surface, time=distance/velocity=L/v Current=total charge/total time=enAL/[L/v]=nAve this is one way to think about it... I hope I helped! ☺️

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Two spherical objects have masses of 3.1 x 10^5 kg and 6.5 x 10^3 kg. The gravitational attraction between them is 65 N. How far

nata0808 [166]

Answer:

4.55 x 10⁹m

Explanation:

Given parameters:

Mass of object 1 = 3.1 x 10⁵kg

Mass of object 2 = 6.5 x 10³kg

Gravitational force = 65N

Unknown:

Distance between them = ?

Solution:

To solve this problem, we use the expression below from the universal gravitational law;

Fg = $\frac{G mass 1 x mass 2}{distance ^{2} }$

G = 6.67 x 10⁻¹¹

65 = $\frac{6.67 x 10^{11} x 3.1 x 10^{5} x 6.5 x 10^{3} }{distance^{2} }$

Distance = 4.55 x 10⁹m

3 0

3 years ago

The air in a room has a pressure of 1 atm, a dry-bulb temperature of 24°C, and a wet-bulb temperature of 17°C. Using the psychro

Licemer1 [7]

Answer:

Given that

Dry-bulb temperature(T) =24°C

Wet-bulb temperature(Tw) = 17°C

Pressure ,P = 1 atm

As we know that psychrometric chart are drawn at constant pressure.

From the diagram

ω= specific humidity

Lets take these two lines Dry-bulb temperature(T) line and Wet-bulb temperature(Tw) cut at point P

From chart at point P

Specific humidity,ω = 0.00922 kg/kg

The enthalpy ( h)

h=47.59 KJ/kg

The relative humidity, RH

RH= 49.58 %

Specific volume ,

v= 0.853 m³/kg

5 0

2 years ago

4. Una cuerda de acero de piano mide 1.60 m de longitud y 0.20 cm de diámetro. ¿Cuál es la tensión en la cuerda si se estira 0.2

bazaltina [42]

Answer:

$1030.83\ \text{N}$

Explanation:

$\Delta L$ = Cambio en la longitud de la cuerda = 0.25 cm

T = tensión en cuerda

A = Área de la cadena = $\dfrac{\pi}{4}d^2$

d = Diámetro de la cuerda = 0.2 cm

L = Longitud original de la cuerda = 1.6 m

El cambio de longitud de una cuerda viene dado por

$\Delta L=\dfrac{TL}{AE}\\\Rightarrow T=\dfrac{\Delta LAE}{L}\\\Rightarrow T=\dfrac{0.25\times 10^{-2}\times \dfrac{\pi}{4}(0.2\times 10^{-2})^2\times 210\times 10^9}{1.6}\\\Rightarrow T=1030.84\ \text{N}$