——What do you think ofthe air in Jinan?
—— It's always above PM2.5.
A:I think so
B:I can't stand it
C:I don't care
D:I hope so
质量为5kg的物体受水平拉力F的作用,物体以10m/s的速度在水平面上沿拉力方向做匀速直线运动.当突然撤去F后,物体经5s停止运动,(g取10m/s2)求: