Can a material have negative permittivity?

Johannes Kepler is known for which discovery in astronomy

Marta_Voda [28]

Answer:

3 laws of planetary motion

7 0

3 years ago

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A hot air balloon is traveling vertically upward at a constant speed of 2.8 m/s. When

swat32

<span>why is your formula x=? if i'm reading it right the formula is the height of the object at time t. That being the case, set your setup (which looks right) equal to 0 and solve for t. This will tell you how long it takes to hit the ground. Plug this value of t into the forumla -9.8t+2.8 and that will tell you the speed at time t.</span>

6 0

3 years ago

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Q14) When you break a bar magnet in half, how many poles does each piece have?

andrew-mc [135]

Each piece of magnet has only two poles, one north and one south. So if you break a bar magnet into two halves, the piece initially consisting the north pole at the edge automatically creates the south pole at the break point and the part consisting south pole creates North pole at the edge. So each piece has 2 poles.

5 0

4 years ago

The National Aeronautics and Space Administration (NASA) studies the physiological effects of large accelerations on astronauts.

m_a_m_a [10]

Answer:

$v = 23.95 m/s$

Explanation:

As we know that when astronaut is revolving in circular path then the acceleration of the astronaut is due to centripetal acceleration

so it is given as

$a_c = \frac{v^2}{R}$

here we know that

$a_c = 4.50 g$

also we know that

$R = 13 m$

now we have

$4.50 \times 9.81 = \frac{v^2}{13}$

$v = 23.95 m/s$

3 0

4 years ago

A solenoid that is 66.1 cm long has a cross-sectional area of 13.8 cm2. There are 1410 turns of wire carrying a current of 8.01

Ymorist [56]

Answer:

a) Energy density of the magnetic field, u = 183.46 J/m³

b) Total energy, E = 0.167 J

Explanation:

a) Number of turns in the solenoid, N = 1410

Area, A = 13.8 cm² = 0.00138 m²

Current, I = 8.01 A

Length of the solenoid, l = 66.1 cm = 0.661 m

Energy density, u is given by the formula $u = \frac{B^2}{2 \mu_{0} }$

Where B is the magnetic field

The magnetic field in a solenoid is given by the formula, $B = \frac{N \mu_{0} I }{l}$

$B = \frac{1410 * 8.01* \mu_{0} }{0.661}$

$B = 17086.38 \mu_0$ T

$u = \frac{(17086.38 \mu_0)^2}{2 \mu_{0} }\\u = \frac{291944527.29 \mu_0^2}{2 \mu_{0} }\\u = \frac{291944527.29 \mu_0}{2 }\\u = \frac{291944527.29 * 4\pi * 10^{-7} }{2 }\\u = 183.46 J/m^3$

b) The total energy = Energy density * Volume

E = u V

Volume = Area * Length

V = Al = 0.00138 * 0.661

V = 0.00091218 m³

E = 183.46 * 0.00091218

E = 0.167 J

4 0

3 years ago