文档介绍：理论力学 Theoretical Mechanics
运动学第七章点的合成运动
力学教研室
Composite Motion of a Point PART B Theorem of Composition of Velocities
Theorem position of velocities
Deduction
Deduction 1
Absolute Displacement 绝对位移
Convected Displacement 牵连位移
Relative Displacement 相对位移
Theorem position of velocities
Deduction
Deduction 2
Theorem position of velocities
Sample problem 1
Sample problem 1
AB moves upward with constant speed u, when it begins moving, j=0, compute the speed of point D when j=p/4, the dimensions are denoted on the figure.
Figure
[solution]
1 chose the proper MP and DF
A—MP, OD—DF;
2 Draw the diagram of velocities
Theorem position of velocities
Sample problem 1
Sample problem 1
[solution]
3 Use the equation to solve the unknowns:
Theorem position of velocities
Sample problem 2
Sample problem 2
A round plate rotates about a fixed point O, the angular velocity w and linear eccentricity (偏心距) e are known, compute the speed of lever AB
[solution]
Step 1 chose proper MP and DF:
MP: point B
DF: round plate
Theorem position of velocities
Sample problem 2
Sample problem 2
[solution]
Step 2 Draw the diagram of velocity:
Step pute the unknowns. Do it in the class.
Theorem position of velocities
Basic procedure of solving:
Basic