Answer:

Explanation:
<u>Gravitational Potential Energy</u>
It's the capacity of an object to do work due to its relative height from a fixed reference point.
It's computed as
GPE=m.g.h
Where m is the mass of the object, h is its height and g is the acceleration of gravity, 
The mass of water is given as

The height above the rocks is h=50 m. Let's compute the GPE


It should be expressed in scientific notation

The GPE at the bottom, where h=0

The change of gravitational potential energy is:


Answer:
Angle between incident ray and reflected ray will be 104°
Explanation:
We have given angle of incidence = 52 °
From law of reflection angle of incidence will be equal to angle of reflection
So angle of reflection will be also 52°
We have to find the angle between incident ray and reflected ray
As the incidence angle and reflected angle both is from normal of the surface and opposite to each other
So angle between incident ray and reflected ray will be 52°+52° = 104°
Forces are considered balanced when all of the combined forces lead to no change in the motion of the object. For example, when a book is sitting on a table, the force of gravity is pushing downward and the normal force is pushing upward with exactly the same amount of force. Since they are equal and opposite forces, the book does not move.
Unbalanced forces exist when there are unequal forces acting upon the object, which leads to a change in the state of motion. Unbalanced forces can lead to a change in direction, a change in speed, or both a change in direction and in speed.