After the box comes to rest at position x₁, a person starts pushing the box, giving it a speed v₁. When the box reaches position x₂ (where x₂>x₁), how much work

has the person done on the box? Assume that the box reaches x₂ after the person has accelerated it from rest to speed v₁. Express the work in terms of m, v₀, x₁, x₂, and v₁.