Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Concepts Of Physics MCQ Edition [Volume 1]PhysicsRotational Mechanics

Starting from rest, a wheel is uniformly accelerated at 4 rad/s ^2 for 10 seconds. Subsequently, it rotates uniformly for the next 10 seconds, and is finally brought to rest over the following 10 seconds. Determine the total angle rotated by the wheel.

Options

  1. A600 rad
  2. B1000 rad
  3. C400 rad
  4. D800 rad

Correct answer

D. 800 rad

Step-by-step solution

The motion of the wheel can be divided into three phases. In the first phase, the wheel starts from rest and accelerates uniformly. Initial angular velocity, ₀ = 0 Angular acceleration, ₁ = 4 rad/s ^2 Time, t₁ = 10 s Angle rotated, ₁ = ₀ t₁ + 1 2 ₁ t₁^2 = 0 + 1 2 4 (10)^2 = 200 rad Angular velocity at the end of this phase, ₁ = ₀ + ₁ t₁ = 0 + 4 10 = 40 rad/s In the second phase, the wheel rotates uniformly. Angular velocity, ₁ = 40 rad/s Time, t₂ = 10 s Angle rotated, ₂ = ₁ t₂ = 40 10 = 400 rad In the third phase,

Practice Rotational Mechanics on Quantrex Academy →

More from Rotational Mechanics

A wheel revolves about its axis with a uniform angular acceleration. Beginning from rest, it attains 100 rev/sec in 4 seconds. Determine the angular acceleration and the angle rotaDetermine the angular velocity of a body rotating with an acceleration of 2 rev/s ^2 as it completes the 5 th revolution after starting.A body rotates about a fixed axis with an angular acceleration of one radian/second/second . Determine the angle through which it rotates during the time in which its angular velocA disc of radius 10 cm rotates about its axis with an angular speed of 20 rad/s . Determine the linear speed of a point situated on the rim.A disc of radius 10 cm rotates about its axis with an angular speed of 20 rad/s . Determine the linear speed of the middle point of a radius.A disc rotates about its axis with a uniform angular acceleration of 4 rad/s ^2 . Determine the radial and tangential accelerations of a particle located 1 cm from the axis at the A block is suspended from a string wrapped on a disc of radius 20 cm , which is free to rotate about its fixed horizontal axis. If the angular speed of the disc is 10 rad/s at a paThree particles, each having a mass of 200 g , are placed at the corners of an equilateral triangle with a side length of 10 cm . Determine the moment of inertia of the system abou Full Rotational Mechanics list All Concepts Of Physics MCQ Edition [Volume 1] PYQs