One way to solve for this quantity is to multiply 8 pi squared times the length of a pendulum divided by 3 times the square of the period of that same pendulum. It is also determined through the use of an Atwood machine, where the difference between the two masses is divided by their sum and multiplied by the acceleration. The period of a simple pendulum is given by the square root of L over this quantity. For 10 points, 
One way to solve for this quantity is to multiply 8 pi squared times the length of a pendulum divided by 3 times the square of the period of that same pendulum. It is also determined through the use of an Atwood machine, where the difference between the two masses is divided by their sum and multiplied by the acceleration. The period of a simple pendulum is given by the square root of L over this quantity. For 10 points, name this quantity, whose value on Earth is 9.8 meters per second squared.
One way to solve for this quantity is to multiply 8 pi squared times the length of a pendulum divided by 3 times the square of the period of that same pendulum.
{g} [accept {acceleration} from {gravity} or equivalents; prompt on “gravity”]