文档介绍:该【质点运动的几种典型形式 】是由【junjun2875】上传分享,文档一共【16】页,该文档可以免费在线阅读,需要了解更多关于【质点运动的几种典型形式 】的内容,可以使用淘豆网的站内搜索功能,选择自己适合的文档,以下文字是截取该文章内的部分文字,如需要获得完整电子版,请下载此文档到您的设备,方便您编辑和打印。一、匀速直线运动(straight line motion with constant velocity)
(常数)
二、匀加速直线运动(straight line motion with constant acceleration)
(常数)
P
O
O1
单击添加标题
点击此处添加正文,文字是您思想的提炼。
自由落体运动(freely falling bodies)
三、抛体运动(projectile motion)
O2
单击添加标题
点击此处添加正文,文字是您思想的提炼。
Path equation:
由于空气阻力,实际射程小于最大射程.
求最大射程
当
真空中路径
实际路径
END
四、圆周运动( circular motion)
1. Angular variables(角量) in circular motion
⑴ Angular position
Position function
Angular displacement
Direction: defined in the direction of advance of a right-handed screw
Caution
A finite angular displacement is not a vector, an infinite angular displacement is!
Reason:
(disobey the Commutative law)
⑵ angular velocity & angular acceleration
-rad
--1
--2
Units:
角速度:
角加速度:
Counterclockwise(逆时针): positive direction
Clockwise(顺时针) : negative direction
Two directions:
intrinsic coordinate system(自然坐标系)
Two unit vector are introduced to describe the circular motion:
o
A
is an unit vector tangent (相切)to the circle at A directing to the advance direction and an unit vector is normal to the circle at a (法向 ) directing toward the center O.
Hence(所以), the acceleration of particle is :
(1-23)
Obviously(显然), we have
o
A
Using and , the velocity can be expressed as(表示成):
(1-24).
It is easy to prove the rate of the tangential unit vector to be equal to
t
o
t+t
Prove: when , we have
and are called the tangential acceleration(切向加速度) and normal acceleration(法向加速度) respectively, and their magnitudes are given by
To summarize(总结), we have