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2 years ago

Explain how scientist learned about the magnetic poles of the Earth.

Physics

2 answers:

Makovka662 [10]2 years ago

8 0

Answer:

there are many way but this may help

Explanation:

The tendency of a magnet to align itself in a north-south direction, so giving a magnetic compass, was discovered by the Chinese about 2000 years ago. Then in 1600 William Gilbert published De Magnete, in which he concluded that the earth behaved as a giant magnet. ...

maks197457 [2]2 years ago

4 0

Answer: Larmor suggested in 1919 that a self-exciting dynamo could explain the magnetic field of the earth, as well as that of the sun and other stars, but it was Elsasser and Bullard in the 1940s who showed how motion in the liquid core of the earth might produce a self-sustaining magnetic field. By this time seismology and other studies had given a clearer picture of the earth, as having a solid inner core, a liquid outer core, both with a composition more of metal (mainly iron) than rock, and a rocky mantle, all below a thin crust that is all we can directly see. Energy from radioactivity travels outwards as heat, producing thermal convection in the core. It seems that this convection is the cause of the earth's magnetic field, although our knowledge of the core and its dynamics is sketchy. Our knowledge is limited to saying that flow regimes like those that may be occurring in the core can produce self-sustaining dynamos, with characteristics similar to that needed to produce the earth’s magnetic field.

Explanation:

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A ball is thrown straight up from the ground with an unknown velocity. It reaches its highest point after 5.5 s. With what veloc

Maslowich

V = u + at
0 = u -9.8 x 5.5
u = 9.8 x 5.5 = 53.9 m/s

5 0

3 years ago

The potential difference between two equipotential lines 5.0 mm apart has a value of 1.2 V, calculate the electric field value.

jonny [76]

Answer:

The electric field value is 240 N/C

Explanation:

Given that,

Distance = 5.0 mm

Potential difference = 1.2 V

We need to calculate the electric field value

Using formula of potential difference

$\Delta V=Ed$

$E=\dfrac{\Delta V}{d}$

Where, E = electric field

V = potential difference

d = distance

Put the value into the formula

$E=\dfrac{1.2}{5.0\times10^{-3}}$

$E= 240\ N/C$

Hence, The electric field value is 240 N/C

6 0

3 years ago

A book sits on a bookshelf without moving until a student picks it up. Which law best explains why the book remains at rest unti

svetoff [14.1K]

Answer:

Newtons first law

Explanation:

object in rest stays at rest

object in motion stays in motion

8 0

3 years ago

A disk of mass M and radius R rotates at angular velocity ω0. Another disk of mass M and radius r is dropped on top of the rotat

AleksandrR [38]

Answer:

$\omega = \frac{(R^2\omega_o}{(R^2 + r^2)}$

Explanation:

As we know that there is no external torque on the system of two disc

then the angular momentum of the system will remains conserved

So we will have

$L_i = L_f$

now we have

$L_i = (\frac{1}{2}MR^2)\omega_o$

also we have

$L_f = (\frac{1}{2}MR^2 + \frac{1}{2}Mr^2)\omega$

now from above equation we have

$(\frac{1}{2}MR^2)\omega_o = (\frac{1}{2}MR^2 + \frac{1}{2}Mr^2)\omega$

now we have

$\omega = \frac{MR^2\omega_o}{(MR^2 + Mr^2)}$

$\omega = \frac{(R^2\omega_o}{(R^2 + r^2)}$

6 0

3 years ago

John and Caroline go out for a walk one day. This graph represents their distance from home.

Serga [27]

Answer:

Option C is the correct answer.

Explanation:

We have velocity of a body = Change in position/ Time.

Considering first portion of graph,

Change in position = 30 - 0 = 30 m

Time = 0.75 hours = 45 minutes = 2700 seconds

Velocity = 30/2700 = 0.011 m/s

Considering second portion of graph,

Change in position = 30 - 30 = 0 m

Time = 0.5 hours = 30 minutes = 1800 seconds

Velocity = 0/1800 = 0 m/s

Considering third portion of graph,

Change in position = 0 - 30 = -30 m

Time = 0.75 hours = 45 minutes = 2700 seconds

Velocity = -30/2700 = -0.011 m/s

So firstly they walked in one direction(positive direction), then they were still(velocity is zero), then they walked in the opposite direction( velocity is negative).

Option C is the correct answer.

3 0

3 years ago

Read 2 more answers