Check<br> Which statements explain why theories change over time? Check all that apply.

An electromagnetic wave is transporting energy in the negative y direction. At one point and one instant the magnetic field is i

natali 33 [55]

Answer:. Option c

Explanation: the speed of an electromagnetic wave is simply the vector product of the magnetic field and the electric field.

The direction of the velocity is the direction of the electromagnetic wave.

The wave is already moving towards the negative y axis (-j) and the magnetic field is already pointing towards the positive x axis (i)

From cross product of unit vectors

i × j = k

i × k = - j

With the second identity, we can see that the electric field will be pointing towards the positive of the x axis (k).

Option c is validated

4 0

3 years ago

To get an idea of the size of magnetic fields at the atomic level, consider the magnitude of the magnetic field due to the elect

artcher [175]

Answer:

The magnetic field is 14.08 T.

Explanation:

Given that,

Speed of electron $v=2.2\times10^{6}\ m/s$

Distance $d =0.5\times10^{-10}\ m$

Suppose we need to find the magnetic field at the location of the proton

We need to calculate the magnetic field

Using formula of magnetic field

$B = \dfrac{\mu_{0}I}{2r}$ ....(I)

Using formula of current

$I=\dfrac{q}{T}$

Using formula of time

$T= \dfrac{2\pi r}{v}$

Put the value of current and time in equation (I)

$B=\dfrac{\mu \times q\times v}{2\pi r\times2r}$

Put the value into the formula

$B=\dfrac{4\pi\times10^{-7}\times1.6\times10^{-19}\times2.2\times10^{6}}{4\pi\times(0.5\times10^{-10})^2}$

$B=14.08\ T$

Hence, The magnetic field is 14.08 T.

3 0

3 years ago

Does an object which is positively charged contains all protons and no electrons?

Aleonysh [2.5K]

Answer:

Positively charged objects have electrons; they simply possess more protons than electrons.

Explanation:

2. An object that is electrically neutral contains only neutrons. Electrically neutral atoms simply possess the same number of electrons as protons.

<h3>Information:</h3>

If an atom has an equal number of protons and electrons, its net charge is 0. If it gains an extra electron, it becomes negatively charged and is known as an anion.

If it loses an electron, it becomes positively charged and is known as a cation.

<h2>I hope this answers help you! :></h2>

7 0

3 years ago

Read 2 more answers

At the same amplitude or volume, which sound would have the highest frequency?

weqwewe [10]

Dog whistle ..................

5 0

3 years ago

A charge of −25µC is distributed uniformly over the surface of a spherical conductor of radius 12.0 cm. Determine the electric f

Bond [772]

Answer:

a) 0 b) 0 c) -9*10⁵ N/C

Explanation:

a)

In electrostatic conditions, no electric field can exist inside a conductor.
As the distance r=5 cm falls inside the conductor, the electric field is just zero.

b)

Same as above, as r=10 cm is still inside the spherical conductor.

c)

At r= 50 cm. from the center of the spherical conductor, we can apply Gauss' Law in order to get the value of the electric field.
By symmetry, the electric field, at a same distance from the center, must be radial, and constant on a spherical surface concentric with the spherical conductor.
So, we can write the following equation for Gauss'Law:

$\int\ {E} \, dA = \frac{Q}{\epsilon_{0} }$

If E is constant, we can take it out of the integral, and integrate all the closed spherical surface, as follows:

$E* 4*\pi *r^{2} =\frac{Q}{\epsilon_{0}}$

So, we can solve for E, as follows:

$E = \frac{Q}{4*\pi*r^{2}*\epsilon_{0}} = \frac{(-25e-6)C}{4*\pi*(0.5m)^{2}*8.85e-12C2/N*m2}}\\\\ E = -9e5 N/C$

E = -9*10⁵ N/C (radially inward, taking the outward direction as positive)

8 0

3 years ago

Check Which statements explain why theories change over time? Check all that apply.