Two blocks of masses 20 kg and 8. 0 kg are connected together by a light string and rest on a frictionless, level surface. Attached to the 8. 0-kg mass is a second light string, which a person uses to pull both blocks horizontally. If the two-block system accelerates at 1. 0 m/s2, what is the tension in the second string attached to the 8. 0-kg mass?.