Method

1. First of all, a rounded connecting rod is placed at the hinge with the smaller radius of circle at the top and the larger radius of circle at the bottom.
2. Then, the rod is set at an angle of. Next, release the rod and at the same moment time is taken for ten swings. This action is repeated at the opposite side and the average reading for ten swings is then calculated.
3. Later, the rounded connecting rod is turned upside down with the larger radius of circle at the hinge and the same steps as above are repeated.
4. After the first experiment has been done, the steps are repeated by using rectangular connecting rod and also prismatic thick plane.

 

APPARATUS

 

1

2

3

                          

 

1. Connecting Bar

Total length: 290mm

 

2. Connecting Rod

Total length: 291mm

 

3. Triangle

Total length: 293.55mm

 

4. Stopwatch

Objective

    : To determine the centre of gravity of a connecting rod, as well as the

                           Radius of gyration about the centre of gravity.

Theory            

:  Moment at O:

 

 

 

 

 

 Clockwise order

                                                \           If  is smaller

                           By using the Newton’s Law for the circulation:

 

                            

                         

                        

                         

 

You may observe that this equation will be same as the general equation which is “Simple Harmonic Motion”. Therefore, we can obtain the frequency by using this system as followed below:-

 

             

                         

            Mean while, the periodic time (T) is been taken to complete a swinging, therefore:-

                       Seconds

           

 

 

 

For the rigid body, moment of inertia at point O is:

 

              Where  is the moment of inertia at centre of gravity.

       Where  is the radius of gyration at centre of gravity.

 

We could obtain the radius of gyration of any rigid body with this equation.