Answer:
0.107 m
Explanation:
The magnetic field at the center of a current-carrying loop is given by

where
is the vacuum permeability
I is the current
r is the radius of the loop
In this problem we have
I = 3.40 A is the current in the loop
is the magnetic field at the centre of the loop
So, solving the formula for r we find

The answer you have is right good job 12
Answer:
1.8 × 10⁻⁸ Hm
Explanation:
Given that:
The refractive index of the film = 19
The wavelength of the light = 136.8 μ m
The thickness can be calculated by using the formula shown below as:
Where, n is the refractive index of the film
is the wavelength
So, thickness is:
Thickness = 1.8 μ m
Since,
1 μ m = 10⁻⁸ Hm
So,
Thickness = 1.8 × 10⁻⁸ Hm
Answer:
19.95 J
Explanation:
The center of mass of the ladder is initially at a height of:

The center of mass of the ladder ends at a height of:
=L/2
So, the work done is equal to the change in potential energy which is:
W = PE = 
now 
therefore
W = [mgL/2]×[1 - sin(theta)]
W = [(7.30)(9.81)(2.50)/2]×[1-sin(51°)]
solving this we get
W = 19.95 J