Final answer:
The symbol for the acceleration due to gravity is 'g'. It has an average value of 9.80 m/s², but can vary slightly based on location. The sign of g depends on the chosen coordinate system direction.
Step-by-step explanation:
The acceleration due to gravity is denoted by the symbol g, which is a constant that represents the acceleration of objects due to the Earth's gravitational pull. At the Earth's surface, g is approximately 9.80 m/s², although this value can slightly vary between 9.78 m/s² to 9.83 m/s² based on factors such as latitude, altitude, and local geological variations. However, for most calculations and problems in physics, we use the average value of 9.80 m/s² unless specified otherwise.
The direction of g is always towards the center of the Earth, thereby defining what we consider 'vertical'. Depending on how we set up our coordinate system, g can be positive or negative; for example, if upward is defined as the positive direction, then acceleration due to gravity is a = -g = -9.80 m/s². Conversely, if downward is defined as positive, then a = g = 9.80 m/s².