[填空题]
A 920-kg sports car collides in+-on*vy*1obnn0e) d qv(g3: hx maweqto the rear end of a 23d:mqk : 8y(joh00-kg SUV stopped at a red ligh:jdhy:q (mk8o t. The bumpers lock, the brakes are locked, and the two cars skid forward 2.8 m before stopping. The police officer, knowing that the coefficient of kinetic friction between tires and road is 0.80, calculates the speed of the sports car at impact. What was that speed?(Let A represent the sports car, and B represent the SUV) $\approx$ m/s
