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Finding angle of tilt and tension in a string

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A body of mass 10 kg is suspended by a light inextensible string from the roof of a train. Calculate the tension in the string and its inclination to the vertical when the train
A. moves with a fixed velocity of 36 km/h.
B. accelerates at 2 ms-2,
C. decelerates at 6 ms-2

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Case (a)
The train moves with constant velocity (a = 0)
Let's take the angle of tilt from the vertical be θ
From the first figure, T sin (θ) = ma (forces balances) ............(1)
a = 0 ...

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