physics
mechanics
Easy
Question
From a circular disc of radius R and mass 9M, a small dim of radius R/3 is removed from the disc. The moment of inertia of the remaining disc about an axis perpendicular to the plane of the disc and passing through O is
The correct answer is:
Let 
be the mass per unit area. The total mass of the disc =
Related Questions to study
Physics
The moments of inertia of a thin square plate ABCD of uniform thickness about an axis posing through the centre 0 and perpendicular to the plate are
(where /2, 1 and 14 are, respectively, the moments of inertia about axes I, 2, 3 and 4, where axes are in the plane of the plate)
The moments of inertia of a thin square plate ABCD of uniform thickness about an axis posing through the centre 0 and perpendicular to the plate are
(where /2, 1 and 14 are, respectively, the moments of inertia about axes I, 2, 3 and 4, where axes are in the plane of the plate)
PhysicsMechanics
Physics
Moment of inertia of a rod of mass M and length L about an axis passing through a point midway between centre and end is
Moment of inertia of a rod of mass M and length L about an axis passing through a point midway between centre and end is
PhysicsMechanics
Physics
Three point masses m1 ,m2 and m3 am located at the vertices of an equilateral triangle of side 'a'. What is the moment of inertia of the system about an axis along the altitude of the triangle passing through m1 ?
Three point masses m1 ,m2 and m3 am located at the vertices of an equilateral triangle of side 'a'. What is the moment of inertia of the system about an axis along the altitude of the triangle passing through m1 ?
PhysicsMechanics
Physics
A thin rod of length 4/ and mass 4m is bent at the points as shown in Fig. What is the moment of inertia of the rod about the axis passing through point O and perpendicular to the plane of the paper
A thin rod of length 4/ and mass 4m is bent at the points as shown in Fig. What is the moment of inertia of the rod about the axis passing through point O and perpendicular to the plane of the paper
PhysicsMechanics
Physics
A smooth uniform rod of length L and mass M has two identical beads (1 and 2) of negligible size, each of mass m, which can slide freely along the rod. Initially the two beads are at the centre of the rod and the system is rotating with angular velocity 
about an axis perpendicular to the rod and is passing through its midpoint. There are no external forces when the beads reach the ends of the rod, the angular velocity of the system is
A smooth uniform rod of length L and mass M has two identical beads (1 and 2) of negligible size, each of mass m, which can slide freely along the rod. Initially the two beads are at the centre of the rod and the system is rotating with angular velocity about an axis perpendicular to the rod and is passing through its midpoint. There are no external forces when the beads reach the ends of the rod, the angular velocity of the system is
PhysicsMechanics
Physics
A solid cylinder of mass M and radius R rotates about its axis with angular speed ω. Its rotational kinetic energy is
A solid cylinder of mass M and radius R rotates about its axis with angular speed ω. Its rotational kinetic energy is
PhysicsMechanics
Physics
A wheel of moment of inertia 
is rotating at uniform angular speed of 
. What is the torque required to stop it in one second.
A wheel of moment of inertia is rotating at uniform angular speed of . What is the torque required to stop it in one second.
PhysicsMechanics
Physics
Let 
be a force acting on a particle having position vector 
. Let 
be the torque of this force about the origin, then-
Let be a force acting on a particle having position vector . Let be the torque of this force about the origin, then-
PhysicsMechanics
Physics
The three similar torque (t) are acting at an angle of 120º with each other. The resultant torque will be-
The three similar torque (t) are acting at an angle of 120º with each other. The resultant torque will be-
PhysicsMechanics
Physics
A force of 
Newton acts at a point 
metre from the origin. The magnitude of torque is -
A force of Newton acts at a point metre from the origin. The magnitude of torque is -
PhysicsMechanics
Physics
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?
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?
PhysicsMechanics
Physics
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
PhysicsMechanics
Physics
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
PhysicsMechanics
Physics
PhysicsMechanics
Physics
PhysicsMechanics
