Torque

IMPORTANT

Torque: Overview

This Topic covers sub-topics such as Torque, Angular Momentum, Conservation of Angular Momentum, Torque and Angular Momentum, Angular Momentum of Particle about a Fixed Axis, Torque of a Force about an Axis and, Torque of a Force about a Fixed Point

Important Questions on Torque

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A planet of mass m is in an elliptical orbit about the sun m<<Msun with an orbital period T. If A be the area of orbit, then its angular momentum would be

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If force F=3i^+4j^-2k^ acts on a particle having position vector 2i^+j^+2k^ then, the torque about the origin will be:

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A particle of mass M tied to a string of length L is rotating along a circular path with constant speed ϑ. The torque on the particle is

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A force F=4i^-10j^ acts on a body at a point having position vector r=-5i^-3j^ relative to origin of coordinates on the axis of rotation. If the torque acting on the body about origin is ak^, then find the value of a (in SI units). [Given, F and r are in SI units]

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Which relation is not correct of the following?

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What are the rotational equivalents for the physical quantity force?

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Relation between Torque and angular momentum is similar to the relation between

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A uniform rod AB of length L and mass M is lying on a smooth table. A small particle of mass m strikes the rod with velocity v0 at point C at a distance x from the centre O. The particle comes to rest after collision. If the value of x, so that the point A of the rod remains stationary just after the collision, is L/n, then find n.

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Relation between Torque and angular momentum is similar to the relation between

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What is Angular momentum of a particle?

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A horizontal disc is freely rotating about a vertical axis passing through its centre at the rate of 100 rpm. A  bob of wax of mass 20 g falls on the disc and sticks to it a distance of 5 cm from the axis. If the moment of inertia of the disc about the given axis 2×10-4  kg m2. Find the new frequency of the disc.

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What is Torque of force? Discuss the conditions when it is maximum and minimum.

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State the law of conservation of Angular momentum.

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As shown in the figure, two balls of same mass m are situated at the centre of a tube of mass M and are rotating with a uniform angular velocity ω0. If the balls suddenly come to end of the tube the resultant angular velocity will be :

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A force F=2i^-3k^ acts on a particle at r=0.5j^-2k^. The torque τ acting on the particle relative to a point with coordinates (2.0 m, 0, -3.0 m) is

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The 747 Boeing plane is landing at a speed of 70 m/s. Before touching the ground, the wheels are not rotating. How long a skid mark do the wing wheels leave?

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When a tree is cut, the cut is made on the side facing the direction in which the tree is required to fall. Why?

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A time varying torque 4t N m is applied on an object about a pivot. Change in angular momentum of body till time t=3 s is:

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If net external torque, about a point, acting on the system is zero, then we can surely say

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A uniform rod of mass M and length a lies on a smooth horizontal plane. A particle of mass m moving at a speed v perpendicular to the length of the rod strikes it at a distance of a4 from the centre and stops after the collision. The angular velocity of the rod about its centre just after the collision is

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