A balance is made using a uniform metre scale of mass 100 g and two plates each of mass 200 g fixed at the two ends of the scale (0 cm and 100 cm). The balance is pivoted at the 45 cm mark of the scale. What is the reading error when a 300 g weight is placed in the plate at 0 cm to weigh vegetables placed in the plate at 100 cm?

The moment of inertia of a rigid body depends on:

Consider a flywheel of mass 10 kg, uniform thickness 15 mm, and radius 100 mm. If it rotates at 300 RPM, then the kinetic energy of the flywheel (in Joules) is:

Two small balls with masses m and 2m are attached to both ends of a rigid rod of length d and negligible mass. If the angular momentum of this system is L about an axis passing through its centre of mass and perpendicular to the rod, then the angular velocity of the system is: