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:
The radius of Earth's circular trajectory is
The time for the Earth to travel around the Sun is
Thus the velocity is velocity
From this we can deduce the centripetal acceleration
Angular velocity is
<span>The amount of heat energy needed to increase the temperature of a substance by </span>
<span> is given by:
</span>
<span>
where m is the mass of the substance, Cs is its specific heat capacity and </span>
<span> is the increase in temperature of the substance.
In this problem, we have a certain mass m of gold, with specific heat capacity </span>
<span>, to which we add Q=2825 J of energy. Its temperature increases by </span>
<span>. Therefore, if we re-arrange the previous equation, we can find the mass of the block of gold:
</span>
<span>
So, the correct answer is B.</span>
The answers are 3.3kWh, 1.2kWh, and 120kWh.
Multiply the amount of kW used per hour by the amount of time it was powered and you receive your answer.