Notes, summaries, assignments, exams, and problems for Physics

Gravitational Acceleration and Field Strength

The strength of the gravitational field depends on the amount of mass $M$ causing the field. Let us define a characteristic of the field that depends only on the mass $M$ and the distance $r$ to the point we consider.

Defining Gravitational Field Strength ($g$)

The gravitational field strength, $g$, at a point in space is the force that would act on a unit mass located at that point. Its unit is Newtons per kilogram ($N/kg$). This term is often used interchangeably with gravitational field intensity.

Calculating the Gravitational Field

To determine the gravitational field created by a point mass $M$, we place a test mass $m$ at a point $P$ in space at a distance $r$ from mass $M$. We calculate the force... Continue reading "Fundamentals of Gravitational Force and Field Calculation" »

Energy: Ability to Do Work

Energy: the ability to do work. Energy is a physical quantity that measures the capacity of a system to produce change or perform work.

Energy in Other Sciences

In other sciences, energy is a scalar quantity that is assigned to the state of a physical system. It is used to describe and compare states across different fields and contexts.

Importance of Energy: Life and Health

Importance of energy: life and health depend on energy. Energy helps us and enables work; it is vital for many essential processes and is fundamental to the operation of systems — without energy, many functions would not exist.

Examples of Energy

• Kinetic energy: quantified according to the motion of matter.
• Chemical energy: associated with chemical