SaraNextGen Study App [2022-23]
Last Updated On 23-10-2022 - By Sara

A child is standing with folded hands at the centre of a platform rotating about its central axis. The kinetic energy of the system is . The child stretches his arms so that the moment of inertia of the system doubles. The kinetic energy of the system now is

a)

b)

c)

d)


Question ID - 100212 :-

A child is standing with folded hands at the centre of a platform rotating about its central axis. The kinetic energy of the system is . The child stretches his arms so that the moment of inertia of the system doubles. The kinetic energy of the system now is

a)

b)

c)

d)

1 Answer
5876 Votes
3537

Answer Key : (b) -

(b)

From conservation of angular momentum ( = constant), angular velocity will remain half. As,

The rotational kinetic energy will become half.



Next Question :

A slender rod of mass  and length  is pivoted about a horizontal axis through one end and released from rest at an angle of 30  above the horizontal. The force exerted by the pivot on the rod are the instant when the rod passes through a horizontal position is

a)

along horizontal

b)

 along vertical

c)

 along a line making an angle of with the horizontal

d)

along a line making an angle of with the horizontal


View Topper Answer

We hope we have given the updated helpful answer / content for your query in an easily accessible format to help you in preparing adequately. We do offer free support materials, 10th maths guide, 10th science guide, 10th tamil guide, 10th social guide, 10th english guide, science 10th guide and also for all the classes books and guide to all the students who sign up for SaraNextGen. Apart from traditional textbook queries, we've got conjointly provided further high order level thinking issues, that are seemingly to be expected in boards and competitive exams. It includes conceptual queries, MCQs, Long and short answer type queries, etc. These Questions are designed to learn each student and academics by providing chapter-wise further issues focusing totally on testing conceptual information with applications. Here, we've got provided a number of the necessary ways in which within which the solutions of all the Questions will profit students of class 1 to 12. If you have any queries, drop a message to us and we will get back to you at the earliest.


SaraNextGen