SaraNextGen Study App [2023-24]
Last Updated On [03-11-2023]

A uniform cylinder of mass rests on two rough horizontal planks. A thread is wound on the cylinder. The hanging end of the thread is pulled vertically down with a constant force

a)

Since horizontal acceleration is provided by the friction acting on the cylinder, its translation kinetic energy is equal to work done by this friction

b)

Since moment about instantaneous axis of rotation is produced by force kinetic  is equal to work done by where ismoment of inertia about the instantaneous axis of rotation and  is the angular velocity

c)

Since cylinder is moving, energy is lost against friction

d)

Work done by + work done by friction on cylinder =total KE of the cylinder


Question ID - 100837 :-

A uniform cylinder of mass rests on two rough horizontal planks. A thread is wound on the cylinder. The hanging end of the thread is pulled vertically down with a constant force

a)

Since horizontal acceleration is provided by the friction acting on the cylinder, its translation kinetic energy is equal to work done by this friction

b)

Since moment about instantaneous axis of rotation is produced by force kinetic  is equal to work done by where ismoment of inertia about the instantaneous axis of rotation and  is the angular velocity

c)

Since cylinder is moving, energy is lost against friction

d)

Work done by + work done by friction on cylinder =total KE of the cylinder

1 Answer
5876 Votes
3537

Answer Key : (b,a) -

(b,a)

When force  acts vertically downwards on the thread, the thread unwinds and the cylinder rotates clockwise. Hence, its surface tries to slip over the planks in a backward direction.Hence, a friction comes into existence and acts on the cylinder in a forward direction (rightward direction). It is the only horizontal force acting on the cylinder. Due to the friction, cylinder experiences a rightward translational acceleration.But the point at which the friction acts  remains always at rest, therefore no energy is lost against the friction

Since the work is done by  and no energy is lost against the friction, therefore total kinetic energy of the cylinder at any instant is equal to work done by . Hence, options (a) and (c) are incorrect and option (d) is correct

If  is the moment of inertia of a body about its instantaneous axis of rotation, then the total KE of the rotating body is equal to . Hence, option (b) is correct



Next Question :

There are four terms/figures in the question.  The terms right to the symbol : : have same relationship as the two terms of the left symbol : : Out of the four terms/figure one is missing, which is shown by(?).  Four alternatives are given for each question.  Find out the correct alternative. 

Durandcup : Football : : Ubercup : ?

(a)

Golf

(b)

Badminton

(c)

Hockey

(d)

Chess


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, 11th maths guide 11th maths guide 12th maths guide 10th maths guide, 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