we are given in the problem the following dimensions or specifications
B = 0.000055 T r = 0.25 m constant mu0 = 4*pi*10-7
The formula that is applicable from physics is
B = mu0*I/(2*pi*r) I = 2*B*pi*r/mu0 I = 68.75 Amperes
Answer:600 miles, 12
Explanation: The movement described in the question exhibits that of a polygon. Exhibiting a constant distance and angle with only varying direction until the starting point is reached.
The sum of exterior angles of a polygon = 360 degrees.
Exterior angle of a polygon = (360 ÷ number of sides)
Therefore,
Number of sides = 360 ÷ exterior angle
Exterior angle = 30 degrees
Hence,
Number of sides = 360 ÷ 30 = 12 sides
Since distance traveled of 50 miles is the same for each displacement ;
Total displacement = distance traveled * number of sides
Total displacement = 50 * 12 = 600 miles.
Answer:
Nails are made of iron. Iron consists of 26 protons and 26 electrons. protons are positively charged and electrons are negatively charged, so this force of attraction keeps the electrons together.
If electrons repel from each other, the positively charge protons and nucleus allow them to move in a definite orbit and prevent them flying out of the nail.
Answer:

Explanation:
information we know:
Total force: 
Weight: 
distance: 
vertical component of the force: 
-------------
In this case we need the formulas to calculate the components of the force (because to calculate the work we need the horizontal component of the force).
horizontal component: 
vertical component: 
but from the given information we know that 
so, equation these two
and 

and we know the force
, thus:

now we clear for 

the angle to the horizontal is 15.466°, with this information we can calculate the horizontal component of the force:


whith this horizontal component we calculate the work to move the crate a distance of 4 m:

the work done is W=173.48J