Physics
The below picture shows a mother pushing her daughter sitting on a swing. The swing is going through the positions A, B, C where A and C are extreme positions and B is the mean position.
(a) Which is the right position i.e. at A, B or C, for the mother to give a constant periodic push to the swing every time in the forward direction to increase the amplitude of the swing?
(b) Name the phenomenon involved in this.
(c) Explain with this example how this phenomenon helps to increase the amplitude of the swing.
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Answer
(a) At position A, the mother should give a constant periodic push to the swing every time in the forward direction to increase the amplitude of the swing because it is an extreme position where speed of the swing is zero and direction of motion changes from backward direction to forward so at this position direction of motion and direction of push are in parallel while for C it is opposite and B speed is maximum on either direction which can collide with mother and hurt her.
(b) Resonance phenomenon.
(c) The natural frequency of the swing will match the frequency of the force applied by mother this will increase the amplitude.
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