Two point masses of 0.3 kg and 0.7 kg are fixed at the ends of a rod of length 1.4 m and of negligible mass. The rod is set rotating about an axis perpendicular to its length with a uniform angular speed. The point on the rod through which the axis should pass in order that the work required for rotation of the rod is minimum is located at a distance of |
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a) |
0.42 m from the mass of 0.3 kg |
b) |
0.70 m from the mass of 0.7 kg |
c) |
0.98 m from the mass of 0.3 kg |
d) |
0.98 m from the mass of 0.7 kg |
Two point masses of 0.3 kg and 0.7 kg are fixed at the ends of a rod of length 1.4 m and of negligible mass. The rod is set rotating about an axis perpendicular to its length with a uniform angular speed. The point on the rod through which the axis should pass in order that the work required for rotation of the rod is minimum is located at a distance of |
|||
a) |
0.42 m from the mass of 0.3 kg |
b) |
0.70 m from the mass of 0.7 kg |
c) |
0.98 m from the mass of 0.3 kg |
d) |
0.98 m from the mass of 0.7 kg |
(c)
The moment o inertia of the system about axis of rotation is
+
The work done in rotating the rod is converted into its rotational kinetic energy
For work done to be minimum