An open train car, with a mass of 2070 kg, coasts along a horizontal track at the speed 2.39 m/s. The car passes under a loading chute and, as it does so, gravel falls vertically into it for 2.69 s at the rate of 423 kg/s. What is the car's speed vf after the loading is completed? Ignore rolling friction. vf = ? m/s

An open train car, with a mass of 2070 kg, coasts along a horizontal track at the speed 2.39 m/s. The car passes under a loading chute and, as it does so, gravel falls vertically into it for 2.69 s at the rate of 423 kg/s. What is the car's speed vf after the loading is completed? Ignore rolling friction. vf = ? m/s