Question 1
A particle P of mass 0.5 kg is attached to one end of a light elastic spring, of natural length 1.2 m and modulus of elasticity newtons. The other end of the spring is attached to a fixed point A on a ceiling. The particle is hanging freely in equilibrium at a distance 1.5 m vertically below A.
The particle is now raised to the point B, where B is vertically below A and AB = 0.8 m. The spring remains straight. The particle is released from rest and first comes to instantaneous rest at the point C.
Find the distance AC.
(4)