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:
Answer = 30,000 N
EXPLANATION
Applying Newton’s second of law of motion, which in summary, states that t<span>he acceleration of an object... is directly proportional to the magnitude of the net force... and inversely proportional to the mass of the object.
</span><span>
Therefore, Force = Mass * Acceleration
F = ma
Mass, m = </span><span>3,000 kg
</span>Acceleration, a = <span>10 m/s</span>²<span>
</span>Force, F = 3,000 × 10
= 30,000 N
the symbol of mass is similar to meter but actually it is different,ve careful
The answer to this is electric force. Hope it helps
