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3 years ago

What needs to be the relation between the two forces to cause the upper magnet to float without moving?

Physics

1 answer:

OleMash [197]3 years ago

7 0

Answer:

If it points the other way, the fields subtract, for a lower energy, and so the magnet prefers to turn to point in this way. Magnets in uniform fields feel torques which make them turn around if they are not pointing in the right direction, but there is no net force making the magnet want to levitate.

Explanation:

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An inductor is connected to a 26.5 Hz power supply that produces a 41.2 V rms voltage. What minimum inductance is needed to keep

alexira [117]

Answer:

The minimum inductance needed is 2.78 H

Explanation:

Given;

frequency of the AC, f = 26.5 Hz

the root mean square voltage in the circuit, $V_{rms}$ = 41.2 V

the maximum current in the circuit, I₀ = 126 mA

The root mean square current is given by;

$I_{rms} = \frac{I_o}{\sqrt{2} } \\\\I_{rms} = \frac{126*10^{-3}}{\sqrt{2} }\\\\I_{rms} =0.0891 \ A$

The inductive reactance is given by;

$X_l = \frac{V_{rms}}{I_{rms}} \\\\X_l= \frac{41.2}{0.0891}\\\\X_l = 462.4 \ ohms$

The minimum inductance needed is given by;

$X_l = \omega L\\\\X_l = 2\pi fL\\\\L = \frac{X_l}{2\pi f}\\\\L = \frac{462.4}{2\pi *26.5}\\\\L = 2.78 \ H$

Therefore, the minimum inductance needed is 2.78 H

7 0

3 years ago

Each year, about _____ percent of the arctic sea ice moves south into the greenland sea, where it eventually breaks up and melts

Mekhanik [1.2K]

Its 10% its on quizlet

5 0

4 years ago

Read 2 more answers

A light spring of constant 179 N/m rests vertically on the bottom of a large beaker of water. A 5.32 kg block of wood of density

Digiron [165]

Answer:

Compression of the spring: 0.18 m (downward)

Explanation:

The forces acting on the block of wood are:

- The force of gravity, acting downward, of magnitude $mg$ , where m = 5.32 kg is the mass of the block and $g=9.8 m/s^2$ is the acceleration due to gravity

- The force exerted by the spring, downward, of magnitude $kx$ , where $k=179N/m$ is the spring constant and $x$ is the elongation of the spring

- The buoyant force, upward, of magnitude $\rho V g$ , where $\rho=1000 kg/m^3$ is the water density and V the volume of the block

Since the block is in equilibrium, the net force is zero, so we can write

$mg+kx-\rho V g=0$ (1)

We have to find the volume of the block first. We have:

m = 5.32 kg (mass)

$\rho_w = 622 kg/m^3$ (wood density)

So, the volume is

$V=\frac{m}{\rho_w}=\frac{5.32}{622}=0.0086 m^3$

So now we can re-arrange eq.(1) to find the elongation of the spring, x:

$x=\frac{-mg+\rho Vg}{k}=\frac{-(5.32)(9.8)+(1000)(0.0086)(9.8)}{179}=0.18 m$

So, the spring is compressed by 0.18 m.

7 0

3 years ago

with what speed does a freely falling object dropped from a height of 88.2m hit the ground? how long does it take for it hit the

Kryger [21]

Answer:

Vf = 41.6 [m/s].

Explanation:

To solve this problem we must use the equations of kinematics.

Vf² = Vo² + (2*g*y)

where:

Vf = final velocity [m/s]

Vo = initial velocity = 0

g = gravity acceleration = 9.81 [m/s²]

y = height = 88.2 [m]

Note: The positive sign of the equation tells us that the acceleration of gravity goes in the direction of motion.

Vf² = Vo² + (2*g*y)

Vf² = 0 + (2*9.81*88.2)

Vf = (1730.48)^0.5

Vf = 41.6 [m/s]

6 0

3 years ago

What behavior of light proves that it is a wave? Hint: will this ONLY happen because light is a wave, or could it also be true o

kiruha [24]

It’s red shift and blue shift because This only occurs when the frequency of the wave is made longer or shorter due to the movement of the source relative to the observer

4 0

3 years ago