JEE Advanced 2020 Concept Recapitulation Test 1 Paper 1

The potential energy ϕ in joule of a particle of mass 1kg moving in the x−y plane, obeys the law ϕ=3x+4y, where (x,y) are the coordinate of the particle in metre. If the particle is at rest at (6,4) at time t=0, then (only conservative force are acting on particle).