Q. 51

# A wheel of moment of inertia 0.500 kg-m^{2} and radius 20.0 cm is rotating about its axis at an angular speed of 20.0 rad/s. It picks up a stationary particle of mass 200 g at its edge. Find the new angular speed of the wheel.

Answer :

Given:

Radius of the wheel (r)= 20.0 cm

Moment of inertia (I_{1}) = 0.500 kg-m^{2}

Angular speed (ω_{1}) = 20.0 rad/s

Mass of the particle it picks (m)= 200g

New angular speed (ω_{2}) =?

Since external torque is zero

Rate this question :

The net external torque on a system of particles about an axis is zero. Which of the following are compatible with it?

Physics - ExemplarA simple pendulum of length l is pulled aside to make an angle θ with the vertical. Find the magnitude torque of the weight w of the bob about the point of suspension. When is the torque zero?

HC Verma - Concepts of Physics Part 1A body is in translational equilibrium under the action of coplanar forces. If the torque of these forces is zero about a point, is it necessary that it will also be zero about any other point?

HC Verma - Concepts of Physics Part 1Suppose the platform with the kid in the previous problem is rotating in anticlockwise direction at an angular speed w. The kid starts walking along the rim with a speed u relative to the platform also in the anticlockwise direction. Find the new angular speed of the platform.

HC Verma - Concepts of Physics Part 1