You have been called to testify as an expert witness in a trial involving a head-on collision. car a weighs 690.0 kg and was traveling eastward. car b weighs 520.0 kg and was traveling westward at 74.0 km/h. the cars locked bumpers and slid eastward with their wheels locked for 6.00 m before stopping. you have measured the coefficient of kinetic friction between the tires and the pavement to be 0.750. 1) how fast (in kilometer per hour) was car a traveling just before the collision? (express your answer to three significant figures.)