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Easy

Question

A disc is rotating with an angular velocity $omega$ ₀. A constant retarding torque is applied on it to stop the disc. The angular velocity becomes ( $omega$ ₀/2) after n rotations. How many more rotations will it make before coming to rest?

n
n/2
2n
n/3

The correct answer is: n/3

From third equation, $omega squared equals omega subscript 0 superscript 2 minus 2 alpha theta$
$not stretchy rightwards double arrow left parenthesis omega subscript 0 divided by 2 right parenthesis squared equals omega subscript 0 superscript 2 minus 2 alpha left parenthesis 2 straight n pi right parenthesis$
$not stretchy rightwards double arrow 4 pi straight n alpha equals 3 divided by 4 omega subscript 0 superscript 2 horizontal ellipsis horizontal ellipsis for _ of left parenthesis 1 right parenthesis$
Let no. of rotations before coming to rest =n'
$not stretchy rightwards double arrow 0 equals left parenthesis omega subscript 0 over 2 right parenthesis squared minus 2 alpha left parenthesis 2 pi straight n to the power of straight prime right parenthesis not stretchy rightwards double arrow 4 pi straight n to the power of straight prime alpha equals fraction numerator omega subscript 0 superscript 2 over denominator 4 end fraction horizontal ellipsis. left parenthesis 2 right parenthesis$
$Error converting from MathML to accessible text.$
from (1)/(2) $Error converting from MathML to accessible text.$

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Can’t find what you’re looking for?

A disc is rotating with an angular velocity $omega$ ₀. A constant retarding torque is applied on it to stop the disc. The angular velocity becomes ( $omega$ ₀/2) after n rotations. How many more rotations will it make before coming to rest?

n
n/2
2n
n/3

The correct answer is: n/3

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A beam of length $l$ lies on the +x axis with its left end on the origin. A cable pulls the beam in y-direction with a force $straight F equals straight F subscript 0 left parenthesis 1 minus straight x over ell right parenthesis$ .If the axis is fixed at x = 0 then find the torque

A beam of length $l$ lies on the +x axis with its left end on the origin. A cable pulls the beam in y-direction with a force $straight F equals straight F subscript 0 left parenthesis 1 minus straight x over ell right parenthesis$ .If the axis is fixed at x = 0 then find the torque

An equilateral triangle ABC has its centre at O as shown in figure. Three forces 10 N, 5N and F are acting along the sides AB, BC and AC. Magnitude of F so that the net torque about ‘O’ is zero is

An equilateral triangle ABC has its centre at O as shown in figure. Three forces 10 N, 5N and F are acting along the sides AB, BC and AC. Magnitude of F so that the net torque about ‘O’ is zero is

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Can’t find what you’re looking for?

A disc is rotating with an angular velocity 0. A constant retarding torque is applied on it to stop the disc. The angular velocity becomes (0/2) after n rotations. How many more rotations will it make before coming to rest?

n n/22nn/3

The correct answer is: n/3

From third equation, Let no. of rotations before coming to rest =n' from (1)/(2)

Related Questions to study

A beam of length lies on the +x axis with its left end on the origin. A cable pulls the beam in y-direction with a force .If the axis is fixed at x = 0 then find the torque

A beam of length lies on the +x axis with its left end on the origin. A cable pulls the beam in y-direction with a force .If the axis is fixed at x = 0 then find the torque

An equilateral triangle ABC has its centre at O as shown in figure. Three forces 10 N, 5N and F are acting along the sides AB, BC and AC. Magnitude of F so that the net torque about ‘O’ is zero is

An equilateral triangle ABC has its centre at O as shown in figure. Three forces 10 N, 5N and F are acting along the sides AB, BC and AC. Magnitude of F so that the net torque about ‘O’ is zero is

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A disc is rotating with an angular velocity $omega$ ₀. A constant retarding torque is applied on it to stop the disc. The angular velocity becomes ( $omega$ ₀/2) after n rotations. How many more rotations will it make before coming to rest?

n
n/2
2n
n/3

A beam of length $l$ lies on the +x axis with its left end on the origin. A cable pulls the beam in y-direction with a force $straight F equals straight F subscript 0 left parenthesis 1 minus straight x over ell right parenthesis$ .If the axis is fixed at x = 0 then find the torque

A beam of length $l$ lies on the +x axis with its left end on the origin. A cable pulls the beam in y-direction with a force $straight F equals straight F subscript 0 left parenthesis 1 minus straight x over ell right parenthesis$ .If the axis is fixed at x = 0 then find the torque