Student Login

Home›Chapters›Rotational Motion PYQs›Rotational Kinematics & Dynamics›Question 39

MHT CET 2021 (20 Sep, Shift 2) · Rotational Kinematics & Dynamics

Rotational Kinematics & Dynamics question from MHT CET 2021 (20 Sep, Shift 2)

Q39MHT CET 2021 · 20 SEP · SHIFT 2Easy

Rotational Kinematics & Dynamics

A disc of radius 0.4 metre and mass 1 kg rotates about an axis passing through its centre and perpendicular to its plane. The angular acceleration is 10 rad s $-2$ . The tangential force applied to the rim of the disc is

Show answer and solution

Answer: (a)

Disc: $I = \frac{1}{2}MR^2 = \frac{1}{2} \times 1 \times 0.16 = 0.08$ kg m $^2$
$\tau = I\alpha = 0.08 \times 10 = 0.8$ N m
$F = \frac{\tau}{R} = \frac{0.8}{0.4} = 2$ N
So the answer is (a) 2 N.

Report a mistake

More questions on Rotational Kinematics & Dynamics

A disc of radius 0.4 m and mass one kg rotates about an axis passing through its centre…MHT CET 2021 (20 Sep, Shift 1)
A solid disc of radius 20 cm and mass 10 kg is rotating with an angular velocity of 600…JEE Main 2021 (25 Jul, Shift 2)
Consider a 20 kg uniform circular disk of radius 0.2 m. It is pin supported at its center…JEE Main 2021 (16 Mar, Shift 1)
A cord is wound round the circumference of wheel of radius r. The axis of the wheel is…JEE Main 2021 (26 Feb, Shift 2)
The angular speed of the wheel of a vehicle is increased from 360 rpm to 1200 rpm in 14…NEET 2020 (Phase 2)
If there is a change of angular momentum from 1 J s to 4 J s in 4 s, then the torqueMHT CET 2020 (16 Oct, Shift 1)
A rope is wound around a solid cylinder of mass 1 kg and radius 0.4 m. What is the…MHT CET 2020 (19 Oct, Shift 2)
A uniformly thick wheel with moment of inertia I and radius R is free to rotate about its…JEE Main 2020 (9 Jan, Shift 2)