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2 years ago

A(n) is made with an electromagnet that is free to spin between two permanent magnets

Physics

1 answer:

Grace [21]2 years ago

7 0

Answer:

Like a galvanometer, an electric motor contains (a switch, an electromagnet) that is free to rotate between the poles of a permanent, fixed magnet. 9.

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the term used to measure a change in speed of an object is a. velocity. b. acceleration. c. capacity. d. flow.

Tomtit [17]

The term is acceleration.

(b).

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3 years ago

The inner cylinder of a long, cylindrical capacitor has radius r and linear charge density +λ. It is surrounded by a coaxial cyl

Ulleksa [173]

Hi there!

We can begin by using the equation for energy density.

$U = \frac{1}{2}\epsilon_0 E^2$

U = Energy (J)

ε₀ = permittivity of free space

E = electric field (V/m)

First, derive the equation for the electric field using Gauss's Law:
$\Phi _E = \oint E \cdot dA = \frac{Q_{encl}}{\epsilon_0}$

Creating a Gaussian surface being the lateral surface area of a cylinder:
$A = 2\pi rL\\\\E \cdot 2\pi rL = \frac{Q_{encl}}{\epsilon_0}\\\\Q = \lambda L\\\\E \cdot 2\pi rL = \frac{\lambda L}{\epsilon_0}\\\\E = \frac{\lambda }{2\pi r \epsilon_0}$

Now, we can calculate the energy density using the equation:
$U = \frac{1}{2} \epsilon_0 E^2$

Plug in the expression for the electric field and solve.

$U = \frac{1}{2}\epsilon_0 (\frac{\lambda}{2\pi r \epsilon_0})^2\\\\U = \frac{\lambda^2}{8\pi^2r^2\epsilon_0}$

Now, we can integrate over the volume with respect to the radius.

Recall:
$V = \pi r^2L \\\\dV = 2\pi rLdr$

Now, we can take the integral of the above expression. Let:
$r_i$ = inner cylinder radius

$r_o$ = outer cylindrical shell inner radius

Total energy-field energy:

$U = \int\limits^{r_o}_{r_i} {U_D} \, dV = \int\limits^{r_o}_{r_i} {2\pi rL *U_D} \, dr$

Plug in the equation for the electric field energy density and solve.

$U = \int\limits^{r_o}_{r_i} {2\pi rL *\frac{\lambda^2}{8\pi^2r^2\epsilon_0}} \, dr\\\\U = \int\limits^{r_o}_{r_i} { L *\frac{\lambda^2}{4\pi r\epsilon_0}} \, dr\\$

Bring constants in front and integrate. Recall the following integration rule:
$\int {\frac{1}{x}} \, dx = ln(x) + C$

Now, we can solve!

$U = \frac{\lambda^2 L}{4\pi \epsilon_0}\int\limits^{r_o}_{r_i} { \frac{1}{r}} \, dr\\\\\\U = \frac{\lambda^2 L}{4\pi \epsilon_0} ln(r)\left \| {{r_o} \atop {r_i}} \right. \\\\U = \frac{\lambda^2 L}{4\pi \epsilon_0} (ln(r_o) - ln(r_i))\\\\U = \frac{\lambda^2 L}{4\pi \epsilon_0} ln(\frac{r_o}{r_i})$

To find the total electric field energy per unit length, we can simply divide by the length, 'L'.

$\frac{U}{L} = \frac{\lambda^2 L}{4\pi \epsilon_0} ln(\frac{r_o}{r_i})\frac{1}{L} \\\\\frac{U}{L} = \boxed{\frac{\lambda^2 }{4\pi \epsilon_0} ln(\frac{r_o}{r_i})}$

And here's our equation!

3 0

2 years ago

1. Dos puntos A y B están separados en línea recta 1475 m. Por el punto A pasa hacia el punto B un móvil con una velocidad de 15

ikadub [295]

Answer:

a) 35 sequndos b) M1 = 600m M2 = 875m

Explanation:

Antes de que el otro móvil comience a moverse, el primer móvil ha viajado 5 segundos a una velocidad de 15 m / s.

5 segundos x 15 m / s = 75 metros.

Podemos establecer una ecuación con la información que conocemos. Juntos, en total, los dos recorren 1475 metros.

Voy a representar el tiempo como t. Un móvil ya ha recorrido 75 metros y hará otros 15 t. El otro aún no se ha movido y viajará 25t. Esos tres números se sumarán a 1475.

75 + 15t + 25t = 1475.

Resta 75 de ambos lados y suma términos similares de t: 40t = 1400

t = 35 segundos.

Ahora tome la distancia recorrida por cada vehículo por separado y conecte 35 segundos para t.

Primer móvil: 75 + 15t = 75 + 15 (35) = 600m

Segundo móvil: 25t = 25 (35) = 875m

Usé un traductor para entender la pregunta y luego traduje lo que escribí. Lo siento si mi explicación no es clara.

6 0

4 years ago

A carousel is moving with uniform circular motion. The centripetal acceleration of the ride is * 1 point circular

finlep [7]

> A carousel is moving with uniform circular motion. The centripetal acceleration of the ride is:

Centripetal acceleration is always directed toward the center of motion

> Where should a force be applied on a lever arm to produce the most torque?

farthest from the axis of rotation

> A boy can raise a rock that weighs 120 N by using a lever and applying a force of 25 N.

What is the mechanical advantage of the lever?

Simply divide the weight by the force applied:

120 / 25 = 4.8

> A pebble that is 3.81 m from the eye of a tornado has a tangential speed of 124 m/s. What is the magnitude of the pebble's centripetal acceleration?

Centripetal acceleration is calculated using the formula:

a = v^2 / r

a = (124 m/s)^2 / 3.81 m

a = 4,035.70 m/s^2 ~ 4036

> A dog sits 1.25 m from the center of a merry go round and revolves at a tangential speed of 2.0 m/s. If the dog's mass is 19.3 kg, what is the magnitude of the centripetal force on the dog?

a = v^2 / r

a = (2.0 m/s)^2 / 1.25 m

a = 3.2 m/s^2

The force is:

F = m a

F = 19.3 kg * 3.2 m/s^2

F = 61.8 N

> A ball attached to a string is whirled in a circle. If the string breaks, what causes the ball to move in a straight line?

The force which is directed away from the center of the motion: centrifugal force

> Find the magnitude of the gravitational force exerted on a 66.5 kg astronaut on the surface of Planet X if the planet has a radius of 4.40 x 10⁶ m and a mass of 8.43 x 10²³ kg.(Use G= 6.67 x 10⁻¹¹ Nm/kg²)

We use the formula:

F = G m1 m2 / r^2

F = 6.67 x 10⁻¹¹ Nm/kg² * (66.5 kg) * (8.43 x 10²³ kg) / (4.40 x 10⁶ m)^2

F = 193 N

> How would the speed of the Earth's orbit change if the Earth's distance from the Sun increased by 9 times?

The orbital speed is related to distance from the formula:

v = sqrt (GM / r)

where r is the distance from Earth to Sun

so if r’ = 9 r

v = sqrt (GM / 9r)

v = (1/3) sqrt (GM / r)

Therefore: Decrease by a factor of 3

> What is the efficiency of a crane that requires 28,000 J of energy to lift a 200 kg object 10 meters?

The total work done is:

Work = 200 kg * 9.8 m/s^2 * 10 m

Work = 19,600 J

So efficiency is:

efficiency = 19,600 / 28,000 * 100% = 70%

> What is the force required to produce a 1.4 Nm torque when applied to a door at a 60.0º angle and 0.40 m from the hinge?

The perpendicular component of the applied force is:

F * sin(60°) = 0.866F N

Since the moment arm is 0.40 m, the torque is:

(0.866F N)*(0.4 m) = 0.3464F N-m

This torque is equal to a value of 1.4 N-m, therefore

0.3464F = 1.4

F = 4.0 N

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3 years ago

Suppose you test a gas in the laboratory. You learn that the gas is made up of carbon atoms and oxygen atoms. Is the gas a compo

Shtirlitz [24]

Maybe, but she hasn't proved it yet. As another example, somebody may bring a jar of gas to your laboratory, and you test the gas in the jar and you find nitrogen atoms, oxygen atoms, argon atoms, and krypton atoms, and there isn't a single compound in it. The gas in the jar is a MIXTURE of gases . . . a mixture that we call "Air".

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3 years ago

Read 2 more answers

A(n) __________ __________ is made with an electromagnet that is free to spin between two permanent magnets

A(n) is made with an electromagnet that is free to spin between two permanent magnets