Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Most Important Selected Qs for JEE AdvancedPhysicsRotational Motion

Two uniform spheres shown in figure rotate separately on parallel axis. The upper sphere has angular speed ₀ and lower sphere is at rest. Now the two spheres are moved together so that their surfaces touch. After a short time the two spheres now in contact are rotating without slipping. Find the final rate of rotation of upper sphere in rad/s. [given moment of inertia of upper sphere I₁=4 ~kg ~m ^2 , moment of inerti

Correct answer

4

Step-by-step solution

When the two disc come in contact, they exert equal and opposite forces. Fadt =I₁ ( ₀- ₁ ) ....(i) Fbdt = I ₂ ₂ ....(ii) finally ₁ a = ₂ ~b l₁ ( ₀- ₁ )=l₂ a^2 b^2 ₁ ₁= l₁ ₀ l₁+ a^2 b^2 l₂ =4 rad / s

Practice Rotational Motion on Quantrex Academy →

More from Rotational Motion

Consider a large disk of radius R and two smaller disks, each of radius r = R/50 , lying on its circumference, as shown in the figure. The smaller disks are initially in contact wi 2026A solid cylinder of radius R rolls without slipping with a center of mass speed v₀ = gR 3 on a horizontal surface with a vertical edge, as shown in the figure. Here, g is the accel 2026List-I shows four planar structures made of uniform solid rods each of mass m and length l . In the List-II the possible moment of inertia of these structures about an axis OCO' , 2026Passage: A uniform circular disk of radius 0.2 m and mass 1 kg is pivoted at its top point C such that it can rotate freely around C in the XY plane, as shown in the figure. Initia 2026Passage: A uniform circular disk of radius 0.2 m and mass 1 kg is pivoted at its top point C such that it can rotate freely around C in the XY plane, as shown in the figure. Initia 2026A solid cylinder having radius R and length L is slipping on a rough horizontal plane. At time t=0 the cylinder has a translational velocity v₀=49 m/s, perpendicular to its axis an 2026A solid sphere ( A ) of mass 5m and a spherical shell ( B ) of mass m , both having same radius, are placed on a rough surface. When a force of same magnitude is applied tangential 2026A solid sphere of radius 4 cm and mass 5 kg is rotating (rotation axis is passing through the centre of the sphere) with an angular velocity of 1200 rpm. It is brought to rest in 1 2026 Full Rotational Motion list All Most Important Selected Qs for JEE Advanced PYQs