Answer:
The fulcrum of the metre stick is at the 40 cm mark
100 g * 10 cm = 1000 g-cm clockwise torque
x * 30 cm = 1000 gm-cm = counterclockwise torque for balance
X = 1000 / (40 -10) = 1000 / 30 = 33.3 gm at 10 cm to balance
Answer:
A) The north pole of a bar magnet will attract the south pole of another bar magnet.
B) Earth's geographic north pole is actually a magnetic south pole.
E) The south poles of two bar magnets will repel each other.
Explanation:
<u>According to </u><u>classical physics</u>, a magnetic field always has two associated magnetic poles (north and south), the same happens with magnets. This means that if we break a magnet in half, we will have two magnets, where each new magnet will have a new south pole, and a new north pole.
This is because <u>for classical physics, naturally, magnetic monopoles can not exist. </u>
In this context, Earth is similar to a magnetic bar with a north pole and a south pole. This means, the axis that crosses the Earth from pole to pole is like a big magnet.
Now, by convention, on all magnets the north pole is where the magnetic lines of force leave the magnet and the south pole is where the magnetic lines of force enter the magnet.
Then, for the case of the Earth, the north pole of the magnet is located towards the geographic south pole and the south pole of the magnet is near the geographic north pole.
And it is for this reason, moreover, that the magnetic field lines enter the Earth through its magnetic south pole (which is the geographic north pole).
B, the light should be travelling out of the optically dense medium to the optically less dense medium.
were d to read "... is greater than the critical angle" I'd agree with it. But it doesn't read that way ...
Which leaves b as the only one which I think is true. Which I find a bit odd.
Out of interest, TIR is often used in piping light down optical fibres, among many other applications.
I think C is the correct answer