A metal pie pan demonstrates the acceleration of gravity.
The first string has equally spaced hardware nuts. As it falls, you will notice that the time between each bang gets shorter and shorter. The second string generates a regular set of bangs, even though the nuts are separated at larger and larger distances. Both strings fall at the same rate. Why do they create differing sound patterns? The nuts fall faster and faster, or accelerate!
The constant pull of gravity causes objects to fall toward the earth's center at a rate of 9.8 meters per second per second, or 9.8 m/sec squared. Simply stated, the farther an object falls toward the earth, the faster it goes. It accelerates. The relationship between time (t), distance (d), and the acceleration constant of gravity (g) is represented by the formula d = 1/2 gt squared. The value of g for the earth's gravitational pull is 9.8 m/sec squared. This formula was used to determine the positioning of the metal nuts on the second string.