2 One end of a light elastic string is attached to a fixed point \(O\). The other end of the string is attached to a particle \(P\) of mass 0.4 kg . The string has natural length 0.6 m and modulus of elasticity 24 N . The particle is released from rest at \(O\). Find the two possible values of the distance \(O P\) for which the particle has speed \(1.5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\).