Answer:
w = -101 rad / s
Explanation:
For this exercise we will use Faraday's law
E = - dФ / dt
where the magnetic flux is
Ф = B. A = B A cos θ
In this case, the angle between the magnetic field and the normal to the disk is zero, cos 0 = 1, they indicate that the field is constant, let's find the area
The area rotated by the disk is
A = ½ r s
if we express the angles in radians
θ = s / r
s = r θ
where is the arc supported
A = ½ r (r θ)
let us substitute in the Faraday equation
E = - d (B ½ r² θ) / dt
E = - ½ B r² dθ/dt
the definition of angular velocity is
w = dθ/dt
E = - ½ B r² w
w = - 2E / B r²
let's calculate
w = - 2 3.86 / (0.0314 1.56²)
w = -101 rad / s
