)革款大串 修德博学 创新 South China Agr icultura l Uni versity MECHANICS Kinematics of particles ° Kinetics of particles Geostatics and Hydromechanics Special relativity Dep physics
MECHANICS • Kinematics of particles • Kinetics of particles • Geostatics and Hydromechanics • Special relativity Dep. physics
苹南癢掌大 但博学求回新 South chi na Agricul tural Uni versity Chap. 1 Kinematics of particles describing motion of particles 1. Base conception 2. Important conception 3. Discussion of curve motion 4 Relative motion
D e p. p h y sic s D e p. p h y sic s D e p. p h y sic s 2 Chap.1 Kinematics of particles ——describing motion of particles 1. Base conception 2. Important conception 3. Discussion of curve motion 4. Relative motion
革擦大寧 但博学一求宣倒新 South chi na Agricul tural Uni versity 1. Base conception Particles to describe an object whose parts all move in exactly the same way. Even a complex object can be treated as a particle if there are no internal motions Reference frame and coordinate frame Vectors a physical quantity that requires the specification of both direction and magnitude
D e p. p h y sic s D e p. p h y sic s D e p. p h y sic s 3 1. Base conception • Particles to describe an object whose parts all move in exactly the same way. Even a complex object can be treated as a particle if there are no internal motions. • Reference frame and Coordinate frame • Vectors a physical quantity that requires the specification of both direction and magnitude
③革由接掌大孝 但博学求回新 South chi na Agricul tural Uni versity 2. Important conception Position vector r(t r=x(1)+y(t)j+(1)k Displacement vector △r=r(t+△t)-r(t)
Dep. physics Dep. physics Dep. physics 4 2. Important conception • Position vector • Displacement vector Z Y X O rZ Y X O 1r 2r r r r(t t) r(t) r r ( t ) r x(t)i y(t) j z(t)k
苹南癢掌大 但博学求回新 South chi na Agricul tural Uni versity ∫=x2+y1+k a=x,i +yaj+zak △ △F=乃h (b -xai +(b-ya)j +(可b-a)k =△x+△y+△xk A=(△)2+(4y2+(△x)2=X=△s cosa=△x △ , CoSy △ F/,cOS △F 5
D e p. p h y sic s D e p. p h y sic s D e p. p h y sic s 5 r x x i b a ( ) xi yj zk z z k b a ( ) br ar y y j b a ( ) rb xb i yb j zbk ra xa i ya j zak 2 2 2 r (x) (y) (z) r z ,cos r y cos ,cos r x r s o br r ar s a b