What is the relationship between the angle of incidence and the angle of refraction when light passes from a medium where its speed is greater into a medium where its speed is lower?

Ahydroelectric plant takes energy from water and turns it into electrical energy. what are the transformations of energy in the water molecules that are used in the process of generating electricity this way?

What is a neurotransmitter involved in mood reward, addiction, and motor behaviors?

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?