FUN-IN SCIENCE EXPERIMENTS

   CENTRIFUGAL  FORCE 

By prof.Samaresh Goswamy 

The  experiment  I am  going  to  write  is primarily  for  school  students.  I would  expect  if parents / grand parents  whohappen to  read  this  they should  share  with  their  school  going  children /grandchildren and  take  interest to  explain  to  them .after  that  I  would  expect  children  to  collect  the  items and perform the  experiment with  their  own hands. 

The  way science  is taught  in many  school  specially  in rural areas  ,where  there  is  no  Laboratory , students  lose  interest  in  science  because  they  can't  understand  merely  by lecture. 

Intention  of these experiments is  to develop  an interest in science  by "doing  the  experiment " and developing  a spirit  of  inquiry  in  them which will  help  them  to  understand & take  active interest  in  learning science. 

WHAT   ARE   NEEDED:

*  Small  Plastic  Bucket

*  3/4 ft. Length  rope 

*  Water 

   WHAT  TO  DO  :

*  Tie  the  rope with the  handle 

*   half  fill the  Bucket  with water 

*  Hold the  string  and  rotate the Bucket around  you  in    a vertical plane

* continue  rotating  for  sometime. 

   WHAT   TO   OBSERVE  :

* Bucket  is inverted completely  at the  highest  point 

*  Water  doesn't  come  out  of  the  Bucket 

   WHAT  IS  GOING  ON ( WHY) :

 When  you  rotating  the  Bucket  you  are  pulling  the  string inward, which  is  producing  CENTRIPETAL FORCE.  Another  FORCE comes into  action trying  to  take  the  Bucket  outward.  This  is  called  CENTRIFUGAL  FORCE  which  is  equal  to  mv²/r ( which  is  shown  in  the  figure  below).

Where  m is mass of  the  Bucket  with  water,  r is radius  of the  path of  the  circle  in  which  Bucket  is  rotating, v is the  velocity. At the  highest  point  of  rotation weight  mg of Bucket  acting  downward  is  counter balanced  by  the  CENTRIFUGAL  FORCE. So  long  as the  weight  of  the  Bucket  with  water is less than  the  CENTRIFUGAL  FORCE. Thus a single  drop  of  water  will not  spill out  of  the  Bucket.