Question bank/JEE Main/Physics

A rotor is rotating with a constant angular velocity ω about its
own axis. At the centre of the rotor a spring is fixed of natural length
(l0) whose other end is connected to a block of mass m. Find the
minimum value of coefficient of friction between block and rotor wall
for which spring remains horizontal. The radius of rotor is R (R >
l0).

A[IMAGE] ω (l0)
m

R (R > l0)

Show answer and solution▾

N = mω2R - K(R - l0)... (1)
For the block to remains in the vertical equilibrium,
[IMAGE] f = mg
⇒ N = mg
⇒ µ(mω2R - K (R - l0) = mg
∴ µ =[IMAGE] TOPIC: CIRCULAR MOTION
SUB TOPIC: DYNAMICS

Source: Grass-G / P-03 Paper 1 (Physics) Eng. + Hindi 24-8-2020.docx