# A string of length  is connected to a fixed cylinder whose top view is shown in Fig. The string is initially slack. The order end of the string (connected to a marble) is moving at a constant velocity of 10 m/s as shown. The string will get stretched at some instant and impulsive tension occurs in the string. If hinge is exerting a force of 40000N for 0.25 ms on the cylinder to bear up the impact of impulsive tension, then mark the correct statements.(Take string to be light, breaking tension of the string is a) The angle made by the velocity of marble with the length of string when it is just stretched is b) The marble will move in a circular path of varying radius with constant speed of m/s, after the string is taut c) To answer above two options, the volume of  must be given d) The string will break if impulse duration is less than 0.05 min

## Question ID - 100806 | SaraNextGen Top Answer A string of length  is connected to a fixed cylinder whose top view is shown in Fig. The string is initially slack. The order end of the string (connected to a marble) is moving at a constant velocity of 10 m/s as shown. The string will get stretched at some instant and impulsive tension occurs in the string. If hinge is exerting a force of 40000N for 0.25 ms on the cylinder to bear up the impact of impulsive tension, then mark the correct statements.(Take string to be light, breaking tension of the string is a) The angle made by the velocity of marble with the length of string when it is just stretched is b) The marble will move in a circular path of varying radius with constant speed of m/s, after the string is taut c) To answer above two options, the volume of  must be given d) The string will break if impulse duration is less than 0.05 min

1 Answer
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Answer Key / Explanation : (a,b,d) -

(a,b,d)

The impulse exerted  by the string on the cylinder is equal and opposite to the impulse exerted by the cylinder on the string

along the string

For marble,

As final velocity of marble along the string is zero

Putting,  we get

The string wraps up around the cylinder and marble moves in a circular path of varying radius with speed . The speed remains constant as only the tension force is present which is perpendicular to the velocity of the marble

For string to break, the impulsive tension has to be

127 votes

127