To solve this task we have to make a proportion, but firstly we have to set up all the main points : so, the distance is s=r(B), that has its <span>r=radius,B=angle in rad
velocity v=ds/dt= w(r)
Do not forget about </span> w = angular speed in rad/s and

Now we can go to proportion




SOLVING FOR A :



or something about <span>10 mph --- SOLVING FOR B.
</span>I'm sure it helps!
I think the answer would be 70
To solve this problem we will apply the concept related to the magnetic dipole moment that is defined as the product between the current and the object area. In our case we have the radius so we will get the area, which would be



Once the area is obtained, it is possible to calculate the magnetic dipole moment considering the previously given definition:



Therefore the magnetic dipole moment is 
You are true, Stokey. The correct choice is<em> (c)</em>.
If you think about it a little bit more, you'll realize that "side to side" is also a horizontal motion.
Anyway, the question told us that we're only talking about 2 dimensions. Well, the The measurements in the 2 dimensions are the x and the y . If there were a z measurement, that would be the 3rd dimension.