
An uniform semi-solid sphere is placed with flat surface on rough inclined plane as shown in the figure. If the friction is large for no sliding, then the minimum angle at which toppling occur is,



Important Questions on Rotational Motion






A football of radius is kept on a hole of radius made on a plank kept horizontally. One end of the plank is now lifted so that it gets tilted making an angle from the horizontal as shown in the figure below. The maximum value of so that the football does not start rolling down the plank satisfies (figure is schematic and not drawn to scale)


A long ladder weighing leans on a frictionless wall. Its feet rest on the floor away from the wall as shown in the figure. If and are the reaction forces of the floor and the wall, then ratio of will be :
(Use .)

A bead of mass stays at point on a wire bent in the shape of a parabola and rotating with angular speed (see figure). The value of is (neglect friction)

A uniform rod of length and mass is balanced on a wedge placed at mark. A mass of is suspended from the rod at and another unknown mass is suspended from the rod at mark as shown in the figure. Find the value of such that the rod is in equilibrium.

A rod of length can rotate about end What is the work done if the rod is rotated by

Shown in the figure is rigid and uniform one meter long rod held in horizontal position by two strings tied to its ends and attached to the ceiling. The rod is off mass and has another weight of mass hung at a distance of from . The tension in the string at is:

Consider a uniform cubical box of side a on a rough floor that is to be moved by applying minimum possible force at a point above its centre of mass (see figure). If the coefficient of friction is , the maximum possible value of for a box not to topple before moving is ________



Consider an obese person bent forward on the ground whose center of mass is at O. The person's hands don't touch the ground. Then friction on the shoes

A bullet of mass m moving with a speed



A uniform rod of mass m and length is suspended by means of two light inextensible strings as shown in figure. tension in one string immediately after the other string is cut is







