如图所示，质点甲以v1＝8m/s的速度从O点沿Ox轴正方向运动，质点_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题计算题

如图所示，质点甲以v₁＝8m/s的速度从O点沿Ox轴正方向运动，质点乙从点（0，60）处开始做匀速运动，要使甲、乙在开始运动后t＝10s在x轴相遇。乙的速度v₂大小为多少？方向与x轴间的夹角为多少？

答案

解：设乙物体速度方向和x轴正方向夹角为θ，经过t＝10s后，两物体的位移大小分别为　　　　

① 　　　　　　　　　　　　　

②

相遇时，沿x轴方向 ③ 　　　　

沿y轴方向 ④

联立上述四个方程可得

听力题

单词拼写：（每小题一分，共10分）

小题1:Fire d_____________ several stores in the business district.

小题2:What’s her a____________ towards the plan? Is she for or against?

小题3: You should not talk about things that don’t c___________ you.

小题4:He is going to make a long j_____________.

小题5:G______________ from our school are working all over the island.

小题6:Dogs _____________(认出) people by their smell.

小题7: It was really very dangerous; you might have __________(伤害)him seriously.

小题8:For him, this will be an ___________ (完全地) new hobby.

小题9: Have you made the examination _________________(日程表)?

小题10:The city lay in _______________(废墟) after the earthquake.

解答题

物体转动就是旋转．______．