IM All Stars for JEE Advanced 2026 - Lecture 6

IM All Stars for JEE Advanced 2026 -Lecture 6 IM All Stars for JEE Mains + Advanced 2026 Aditya Kumar Jha Lesson 6 Mar 2, 2026 PARAGRAPH 1 A frame of reference that is accelerated with respect to an inertial frame of reference is called a non-inertial frame of reference. A coordinate system fixed on a circular disc rotating about a fixed axis with a constant angular velocity is an example of a non-inertial frame of reference. The relationship between the force vec F rot experienced by a particle of mass m moving on the rotating disc and the force vec F in experienced by the particle in an inertial frame of reference is vec F rot = vec F in +2m( vec v rot * vec omega )+m( vec omega * vec r )* vec omega where vec v rot is the velocity of the particle in the rotating frame of reference and vec r is the position vector of the particle with respect to the centre of the disc. Now consider a smooth slot along a diameter of a disc of radius R rotating counter-clockwise with a constant angular speed about its vertical axis through its center. We assign a coordinate system with the origin at the center of the disc, the x-axis along the slot, the y-axis perpendicular to the slot and the z-axis along the rotation axis ( vec omega = omega tilde k ) A small block of mass m is gently placed in the slot at vec r = (R / 2) hat i slot. at t = 0 and is constrained to move only along the R 117 R/2 Q.15 The distancer of the block at time t is (A) (+) R 4 (B) R/2 * cos omega*t (C) R/4 * (e ^ (2omega*t) + e ^ (-2omega*t)) (D) R/2 * cos 2 cot Q.16 The net reaction of the disc on the block is (A) 1 2 m omega^ 2 R (e ^ (2at) - e ^ (-2omega*t)) hat j +mg hat k (B) 1 2 m omega^ 2 R (e ^ (ot) - e ^ (- n * t)) hat j +mg hat k