Question

Need ur help frnds urgently ... Wanna make a working model for science fair plz provide some ideas nd procedures along with images plzzzz helpp i will be very thankful to u ..

Answer 1

u can make models on heart,nerve cell.digestive system  if not some other important organs in our body or else u can make some working models on electric circuit etc or else u can make  models even on plants related to photosynthesis and so on .or else u try to explain how volcanoes erupt my MAKING  MODELS U CAN EVEN MAKE MODELS OF SOLAR SYSTEM IF U WANT

Answer 2

take a wooden plank and tie 2 sytroform cups upside down to it
heat it.
one cup will move slightly upward
this shows that hot air is lighter than cold air 
                                   OR
take an electric motor 
fix a round disc of paper and connect cell to it
when it will spin ask the viewer to draw a straight line with pencil on disc
after they draw stop the motor and show the line
it wont be straight
tell them
hence than its the centrifugal force deflects winds on the earth
                                  OR
on the same disc ask them to balance an eraser
it will fall down 
hence if there was only centrifugal force governing the earth we would also have been thrown away
hence gravitational force is very essential for our existence