1- Small pendulum bob of lead or brass
  tied to a length(l m) of cotton threaded
  through a supporting cork or clamped
  between two small metal plates.


 2- Retort-stand.


 3- clamp.
            

- The ideal simple pendulum consists of
 a point mass suspended by a weightless
 string For a small angular displacement the
 restoring force acting on the point mass
 is given by:

   F = - mg sinө = -mg ө

 (since ө is very small)= mg x/L
 Where x is the displacement,
 L is the length of a pendulum.

- Hence the equation of motion
 is given by:

  g(x/L) = d²x/dt².

- This is an equation of simple harmonic
 motion with periodic time T = 2π√L/g

1- Measure the length of the pendulum this
  the distance from a fixed hang point to
  the center of the suspended bob.

2- The pendulum is given a small
  displacement.

3- The time of 20 swings, measured
  against a fixed mark on the bench,is taken,
  and the periodic time(T) found.

4- This is repeated with different lengths (L)
  of the pendulum.

5- Repeat steps 1-4 at least three times
  for each length and tabulate your results.

6- A graph is drawn between Tav2 and
  L from which an average value of T2/l
  is obtained to determine g.