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A coin is placed on a gramophone record ...

A coin is placed on a gramophone record rotating at a speed of 45 rpm, it flies away when the rotational speed is 50 rpm. If two such coins are placed one over the other on the same record both of them will fly away when rotationalspeed is

A

100 rpm

B

25 rpm

C

12.5 rpm

D

50 rpm

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