JEE Mains 2020 Model Paper 2 New Pattern

A particle of mass 'm' moves in one dimension. Its potential energy is given by U (x) = −U0e−

x2

a2

where U0 and a are constants. Find the speed at the origin (x = 0) such that when the particle reaches x = ± a, it stops momentarily and reverses the direction of its motion :