The potential energy of a particle of mass $5 \mathrm{~kg}$ moving in the $x-y$ plane is given by $U=-7 x+24 y$ joule, $x$ and $y$ being in metre. Initially at $t=0$ the particle is at the origin and moving with velocity $(2 \hat{i}+3 \hat{j}) \mathrm{m} / \mathrm{s}$. The magnitude of the force on the particle and the acceleration of the particle are
(a) $35 \mathrm{~N}, 7 \mathrm{~m} / \mathrm{s}^{2}$
(b) $30 \mathrm{~N}, 6 \mathrm{~m} / \mathrm{s}^{2}$
(c) $25 \mathrm{~N}, 5 \mathrm{~m} / \mathrm{s}^{2}$
(d) None of these