A meter stick is balanced at its centre `(50 cm)`. When two ocoins each of mass ` 5 g ` are put on the top of the other at the `12 cm` mark, it is found to be balanced at `45 cm`. What is the mass of the stick?

Three objects with a mass of 40 kg each are placed in a straight line 50 cm apart. What is the net gravitational force at the centre object due to the other two?

An unknown resistance R1 ​ is connected in series with a resistance of 10 ohm. This combination is connected to one gap of a metre bridge, while other gap is connected to another resistance R2 ​ . The balance point is at 50 cm. Now, when the 10 ohm resistance is removed, the balance point shifts to 40 cm.Then, the value of R1 ​ is

A circular disc of mass 10kg is suspended by a wire attached to its centre. The wire is twisted by rotating the disc and released. The perod of torsional oscillations is found to be 1.5s . The radius of the disc is 15cm . Determine the torsional spring constant of the wire. ( Torsional spring constant alpha is defined by the relation J=-alpha theta , where J is the restoring couple and theta the angle of twist).