Test and analysis: (1) The freight car moves in a straight line at a uniform speed, with initial speed v 0 = 10m/s and acceleration a=2m/s 2. The No.3 terminal speed v is solved by the speed formula.
(2) Calculate the displacement x 6 of the first 6 seconds by the displacement formula, and calculate the average speed by the formula.
(3) Calculate the displacement x 5 of the first 5s by the displacement formula, and the displacement x ⅵ of the truck in the sixth phase = x 6-x 5.
(1) 6s terminal speed V6 = v0+at =10+2x3 =16m/s.
(2) x 6 = V 0 t+ at 2 = 96 m，V=" 16" m/s？
(3)Xⅵ= X 6–X 5 = " 2 1 " m
Comments: This question is a simple application of the law of uniform linear motion. In the same process of uniform change, knowing three physical quantities can solve any unknown number of kinematics.