2 Newtons laws of motion2.1 2.2 2.3 2.4 2.5 1-131-101-8Pope

16616 1665

1667 168412

172732085

=R1 1.

2. ::;:(1) (2) ,,

: F =150Na = 0.2m/s2l = 4mm = 2kg. x..x#

(1) F x = x (t)m = 2kgx =10t 2+2t+1SI3.

: = 0sint , , 0mR c m

m =1kgf =2tt = 0 x0= 0v0=1m/s(2) a. b. F = mdv/dt c.

x0mvFxF= kv k t = 0 x = 0m v0v t = 0 v = v0

4. :1. ?2. ?(:)(:)

(),? : ,

:

()::():()

Tinosa1640004 87511

(1) m(2) (3) (4) :xy:

mM, .mM amMMMm M

MMm xx'y'

----

Ft=mv2 - mv1F2 1.

::(1)F=30,v0=0,v4 =4.16m/s(2)F=7010t, v7 =2.78m/s(3)v6 = 4.24m/s a m =10kgF b = 0.2t = 476s

2. m1m2mn;in

n

= 3. ===

(2) (t,),.(3) ,,.(1)

(M)l, (m),,?xx: (,) ,.,

mdm t t + dt 4.

d tdmdm

(1),(2)(3)(4)(5)12

v =3m/s, m=500kg,?: t m t+dt dm t t+dt: dt ::

m0l , v0F() ()t x , t +dt x+dx t t+dt:

() m dm() t t+dt:

5.

()

(xc yc zc)c

:axc: xdx2y2ydx=2xdxdm=2xdx

x dx2y2ydx=2xdx

= =

F = mac

m1=50kg m2=200kg , l = 4m,d = :,,,,,:

1. .abN,, Fi,:3

tA

x = 8, y = 6 ?

: m =2kgF = 12tN x 3s :x

(1) (2) 2. dvv v

. ml 0m (),PTddr A=

3. EpF F

0xyabcmP a-b-cP Py1y2ha-d-cdmc-b-aadcba, (

mx1x2

12m1m2f112f221:? dt 21 f2dr12

() MmM MOm M

(1)(2) r = r0 fr = 0r > r0 fr < 0r r < r0 fr > 0r

Ni( i =1,2,3N ) N :4. .

l m

:(1);(2)(3)(4)(5);(6)

kmv0mgNfF mgNf F2xmaxk mv0xmax .1

:m L, ,,a, ,,: ; (1)=++;(2)(3)(4)():

(5)(6)

()4 1.

2. M0

3.

(,)

: ,,1,r1 ;r2,2 .0r11r2:0,0.,0.

:(,)0 0::..-----.,4

, (),, ,L L,,,L