This book is intended for being used as a textbook or reference book at the level of first-year graduation-level Physics or engineering. The objective is to provide a set of comprehensive materials that would help the student to grasp the concepts. The prerequisite for this book is pre-university Mathematics and Physics.
Every particle of matter in the universe attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of their distance apart.
Gravitational field of a body is the space around it within which its gravitational force of attraction is perceptible. Gravitational intensity at a point in the field due to a body is the force experienced by a unit mass at that point.
The gravitational potential at a point in the gravitational field due to a body can also be defined as the potential energy of an unit mass placed at that point. The highest value of the potential (gravitational) is zero at infinity.
Equipotential surface is the surface at every point on which the gravitational potential has the same value. This means that no work is done in moving a unit mass or any mass along the equipotential surface.