Show that the value of acceleration due to gravity of the earth, g= 9.8m/s 2
Answers
Objective:
To measure (g) by measuring the period of oscillations of a simple pendulum
Equipment:
A computer with Internet connection, a calculator (The built-in calculator of the computer may be used.), paper, and pencil
Theory:
Gravity exerts a force on every object. This force is proportional to the mass of the object. The proportionality constant is the acceleration of gravity "g." The gravity acceleration (g) decreases with increasing elevation; however, for a few thousand feet above the Earth's surface, it remains fairly constant. In this experiment, a simple pendulum will be used to measure "g ." A simple pendulum is made of a long string and a tiny metal sphere, steel or preferably lead (higher density). The period of oscillation of a simple pendulum may be found by the formula
As the first formula shows, the stronger the gravitational pull (the more massive a planet), the greater the value of g , and therefore, the shorter the period of oscillations of a pendulum swinging on that planet. If the pendulum has a steel ball, and a magnet is placed underneath the arc where it travels back and forth as it swings, the pace of oscillation does change and it swings faster. Swinging faster results in a shorter period T. Symbol g is in the denominator. A greater g means a smaller T.
Procedure: Note: The applet you open has an error in it. The correct unit for the length of pendulum is (cm) and not (m) as shown in the applet.