A particle with charge +7.60nC is in a uniform electric field directed to the left. Another force, in addition to the electric force, acts on the particle so that when it is released from rest, it moves to the right. After it has moved 8.00 cm, the additional force has done 6.50×10⁻⁵
J of work and the particle has 4.35×10⁻⁵ J of kinetic energy.

(a) What work was done by the electric force?