Would u explain one thing to me which is why it stops rotating after some time and this is because loss of energy in string but when it stops rotating then why it do not start to rotate again as earlier it was started from rest.

Would u explain one thing to me which is why it stops rotating after some time and this is because loss of energy in string but when it stops rotating then why it do not start to rotate again as earlier it was started from rest.

when the mass rotates first , it twists the (mono-filament) string, the string is not free , it will resist the rotation after a while, however it will start to rotate again after you release the potential energy from the string by hand.

when the mass rotates first , it twists the (mono-filament) string, the string is not free , it will resist the rotation after a while, however it will start to rotate again after you release the potential energy from the string by hand.

I wasn't mean that i meant when u release the string (free of any twist) the mass starts rotating then twisting occurs which resist the motion and then it rotates in opp. direction and this process continues for a long time and then rotation stops and mass is at rest . I wanted to know why it stopped and not started rotating again due to earths rotation

I wasn't mean that i meant when u release the string (free of any twist) the mass starts rotating then twisting occurs which resist the motion and then it rotates in opp. direction and this process continues for a long time and then rotation stops and mass is at rest . I wanted to know why it stopped and not started rotating again due to earths rotation

do you mean it should rotate towards both directions , switching from counterclockwise to clockwise , and vice versa and doing this forever? If you mean so,

 

this will not happen, the earth rotation affect towards a single direction , and not both directions, either counterclockwise north the equator or clockwise south the equator, it starts at rest and rotates counterclockwise ( In the US, I guess), it switches direction , because it possessed kinetic energy and created potential energy in the string this potential will enable it to rotate clockwise , during it rotates in the opposite direction(clockwise), the earth rotation effect is still affecting on it , so it will not go further as it should be, doing this will cause it to loose its kinetic energy, until it stops. when it is finally at rest , there will be the rotation effect , which is counterclockwise affecting continuously , even though it is at rest , and also there is a little twisting which gives the mass a force towards clockwise direction, these two are equal in value and are opposite in directions , the earth rotational effect and the potential energy so the mass will finally stops. To ensure of the existing of the potential twisting energy in the string, untie the string and you will see it rotating , the string itself not the mass.

Ok now I get it and thanks for ur reply and answer .