Dan confirms the authenticity of an amethyst stone by a few tests. during one of the tests, he finds the angle of the refracted ray of light coming out of the amethyst into the air as 28°. if the refractive index of amethyst is 1.55, what is the incident angle?

Amass attached to a spring is displaced from its equilibrium position by 5cm and released. the system then oscillates in simple harmonic motion with a period of 1s. if that same mass–spring system is displaced from equilibrium by 10cm instead, what will its period be in this case? a mass attached to a spring is displaced from its equilibrium position by and released. the system then oscillates in simple harmonic motion with a period of . if that same mass–spring system is displaced from equilibrium by instead, what will its period be in this case? a) 0.5sb) 2sc) 1sd) 1.4s