Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
BITSAT2021PhysicsRotational MotionActual

Three particles, each of mass m gram, are situated at the vertices of an equilateral triangle A B C of side ~cm (as shown in the figure). The moment of inertia of the system about a line A X perpendicular to A B and in the plane of A B C , in gram - cm ^2 units will be

Options

  1. A3 2 m l²
  2. B3 4 m l²
  3. C2 m l²
  4. D5 4 m l²

Correct answer

D. 5 4 m l²

Step-by-step solution

I _ AX = m ( AB )²+ m ( OC )²= m l²+ m (l 60^ )²=m l²+ m l² 4 = 5 4 ~m l²

Practice Rotational Motion on Quantrex Academy →

More from Rotational Motion

The moment of inertia of a cube of mass m and side a about one of its edges is equal to 2024The torque of a force 5 i +3 j -7 k about the origin is . If the force acts on a particle whose position vector is 2 i +2 j + k , then the value of will be : 2023A disc is rolling without slipping on a surface. The radius of the disc is R . At t=0 , the top most point on the disc is A as shown in figure. When the disc completes half of its 2023Four holes of radius 5 ~cm are cut from a thin square plate of 20 ~cm and mass 1 ~kg . The moment of inertia of the remaining portion about Z -axis is 2022A solid sphere of 80 ~kg and radius 15 ~m moving in a space becomes a circular disc of radius 20 ~m in 1 ~h . The rate of change of moment of Inertia in this process is 2022A round disc of moment of inertia I ₂ about its axis perpendicular to its plane and passing through its centre is placed over another disc of moment of inertia I ₁ rotating with an 2021A solid cylinder and a hollow cylinder both of the same mass and same external diameter are released from the same height at the same time on an inclined plane. Both roll down with 2020M.I of a circular loop of radius R about the axis in figure is 2020 Full Rotational Motion list All BITSAT PYQs