Answer with Explanation:
We are given that




a.Length of segment,l=20 m
Magnetic force ,F=

Substitute the values

Hence, the magnetic force exert by each segment on the other=0.0119 N
b.We know that when current carrying in the wires are in same direction then the force will attract to each other.
Hence, the force will be attractive.
The gravitational force is inversely proportional to the
square of the distance between their centers. So the
force is greatest when the distance is zero.
I have no idea I need the answer too
Answer with Explanation:
We are given that mass of block=0.0600 kg
Initial speed of block=0.63 m/s
Distance of block from the hole when the block is revolved=0.47 m
Final speed=3.29 m/s
Distance of block from the hole when the block is revolved=
a.We have to find the tension in the cord in the original situation when the block has speed =

Because tension is equal to centripetal force
Substitute the values

b.

c.Work don=Final K.E-Initial K.E



To develop this problem it is necessary to apply the concepts related to a magnetic field in spheres.
By definition we know that the magnetic field in a sphere can be described as

Where,
a = Radius
z = Distance to the magnetic field
I = Current
Permeability constant in free space
Our values are given as
diameter of the sphere then,

Thus z = a



Re-arrange to find I,



Therefore the current at the pole of this sphere is 