The diagram shows a ray of light striking a mirror that is above a sink full of water explain what what will happen to the beam of light as it leaves the mirror and then enters the water

According to the law of reflection, the angle of incidence is the angle between the line normal (or perpendicular) to the surface and the light interacting with the surface of the water  . So the angle of the light to the mirror will be equal to that of the mirror reflecting light into the water.

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.