The answer will be Amplitude.
I think it would be A, because it is moving the slowest then. But get a second opinion.
Answer:
W = 2.5*10⁻⁴ J (by me)
Explanation:
μy = 5.0 x 10⁻⁴ A·m²
By = 0.5 T
∅ = 0º
If
μx = 5.0*10⁻⁴ A·m²
By = 0.5 T
∅ = 90º
We get ΔU as follows
ΔU = Uf - Ui
Ui = - μy*By*Cos ∅ = - 5.0*10⁻⁴ A·m²*0.5 T*Cos 0º = - 2.5*10⁻⁴ J
Uf = - μx*By*Cos ∅ = - 5.0*10⁻⁴ A·m²*0.5 T*Cos 90º = 0 J
Finally we use the equation
W = - ΔU = - (0 - (- 2.5*10⁻⁴)) J = - 2.5*10⁻⁴ J (by the field)
W = 2.5*10⁻⁴ J (by me)
The phenomenon which is responsible for this effect is called diffraction.
Diffraction is the ability of a wave to propagate when it meets an obstacle or a slit. When the wave encounters the obstacle or the slit, it 'bends' around it and it continues propagate beyond it. A classical example of this phenomenon is when a sound wave propagates through a wall where there is a small aperture (as in the example of this problem)
The answer is A. Cones, as rods are not sensitive to color. :)