Consider a spiral horizontal coil , center of gravity of which is supported by table at point G. The end of coil E has been brought near point G and a body is hanging right over point G at negligible height but the horizontal coil and body is completely separated by space except at supporting point G. Let mass of spiral coil be m and mass of body be m'. Let length of spiral coil from point G to end E be L. Let speed of compression wave in material of spiral coil be c. The spiral coil, hanging body, table comprises system and intitially the system is in state of static equilibrium. As mass of coil and body is m+m', point G on table is supporting weight (m+m')g. At t = 0, we begin to release the body and at t = t' the body is completely supported by table at point G and is in state of static equilibrium. That means there is no contact between body and end E of spiral coil. Gravity is acting on this body and weight m'g is acting on point G at t = t'. As the body touches the table, this information will begin to be transmiteed through decompression waves starting from point E to point G and will reach point G after time interval t whete t = L/c. Let total transmission time of compression waves (t) is much much greater than total release time of body(t'). Hence t >> t'. Let blackout time T = t-t'. During this blackout time T, the point G has absolutely no information about events happening at point E of coil. Hence weight (m+m')g is acting on point G during this black out time T. So total weight acting on point G during blackout time T is (m+m')g + m'g = (m+2m')g. Suppose the weight (m+m')g is not enough to break down table at point G. But weight (m+2m')g is enough to break the table. My question is, will the table break down during blackout time T? -Abhi. Abhijit B Patil, India. Email: sciphysics@yahoo.co.in
