(a) State the conditions for the equilibrium of a rigid body acted upon by parallel forces.

(b)(i) Describe an experiment to determine the mass of a metre rule using the principle of moments.

(ii) State two precautions necessary to obtain accurate results in the experiment described in (b)(i) above.

(c) A bullet of mass 120 g is fired horizontally into a fixed wooden block with a speed of 20 ms\(^{-1}\). If the bullet is brought to rest in the block in 0.1s by a constant resistance, calculate the (i) magnitude of the resistance; (ii) distance moved by the bullet in the wood.