重点放在极限问题、积分上。题目主要看 CHAPTER5中的例题。 a ring screen of radius r is horizontally fastened on a frictionless surface. a slippy block of mass m moves along its inner-wall. The frictional constant between them is u Find: (a) when the speed of block is v, Frictional force f? anda=?(b) How long will it take as its(滑块) speed decreases y→)w3? Solution (a) Using natural coordinate frame N R
重点放在极限问题、积分上。题目主要看CHAPTER 5中的例题。 A ring screen of radius R is horizontally fastened on a frictionless surface. A slippy block of mass m moves along its inner-wall. The frictional constant between them is . Find: (a) when the speed of block is v, Frictional force f=? and at =? (b) How long will it take as its(滑块)speed decreases v→ v/3? N v Ft R O v m (a) Using natural coordinate frame Solution:
Chapter 6 gravitation Page132-146 不要求
Chapter 6 Gravitation Page132-146 不要求
Chapter 7&8: Work and energy p147-160
Chapter 7&8: Work and Energy p147-160
7-1 Work done by a constant Force P147-P151 >Work done by several forces: if F=F+F2+F3+F4+ W=∫FdF=「F1dP+∫F2dF+∫F3:dF+ =W1+形,+W2+ The work done by several forces =algebraic sum of the work done by the individual force
7-1 Work Done by a constant Force P147-P151 if F = F1 + F2 + F3 + F4 + = + + + = = + + + 1 2 3 1 2 3 W W W W F d r F d r F dr F dr The work done by several forces = algebraic sum of the work done by the individual force. ➢Work done by several forces:
Special expression in scalar product F=Fxi+F,j+Fik, and dr=dxi +dyj+dik W=∫FdF=∫3(Fx+F4+Fd) ∫Fx+F小+F
, and ˆ ˆ ˆ F = Fx i + Fy j + Fz k . ˆ ˆ ˆ dr = dxi + dy j + dzk = + + = = + + f z i z z f y i y y x f xi x B A x y z B A F d x F d y F d z W F dr (F d x F d y F d z) ➢ Special expression in scalar product: