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    21-Jul-2015
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Transcript of ±€±½„®ƒµ¹‚...

  • 1

    2015

    1. iv.

    ! = ,

    , ! = .

    2. :

    i. ! !a :

    ii. ! !a :

    iii. ! !a : ( )

    v. ! = 0 ,

    !a 0 : - ( )

    vi. ! = ,

    !a = .:

    . T - F, - , - xo, - U = 4 J = 1 J. -, - - , .

  • 2

    E = K +U E = 5 J

    , x1, U1 = - 2 J , :

    E = K1 +U1 5= K1 + (2) K1 = 7J

    A. t - - , - , x - . , , . , :

    x

    = 2r x

    ()2 = x(2r x) (1)

    : ( )2= x2 + ()2 ()2 = ( )2 x2 (2)

    (1), (2) :

    ( )2 x2 = x(2r x) ( )2 x2 = 2rx x2 ( )2 = 2rx x = ( )

    2

    2r (3)

    1. (3), ( ) = t , :

    x =

    ( )22r

    x = 2

    2rt (4)

    , -:

    =

    2

    2r

  • 3

    2. (3), ( ) = t , :

    x =

    ( )22r

    x = 2

    2rt2 (5)

    - :

    =

    2

    r

    . - - r R (R>r).

    B1. , , - , :

    = x

    A= y

    AE (1)

    (1), A = t ,

    x =

    2

    2rt . -

    AE = t , y =

    2

    2Rt . :

    xA

    = yAE

    2t2r t

    =

    2t2R t

    r=

    R

    = r

    R

    B2. x = y. :

    x = y

    2t2r

    = 2t

    2R

    2

    r=

    2

    R

    = r

    R

    B3. , :

  • 4

    x = 2r

    2t2r

    = 2r t = 4r2

    2

    - .

    A. () - x0 = 0 x , uo u :

    K K A =WF

    12

    mu2 12

    muo2 = F x u2 = uo

    2 2 Fm

    x

    , F/m () :

    u2 = uo

    2 2 x (1)

    (1), x = 0 ( ) :

    u2 = uo

    2 2 x u2 = uo2 uo = 10 m / s

  • 5

    , x = 25 m u = 0, - :

    u 2 = uo

    2 2 x 0 = 100 2 25 50 = 100 = 2 m / s2

    B. Y x1 t1 = 9 s:

    x1 = uot1

    12

    at12 x1 = 10 9

    12

    2 81 x1 = 9081 x1 = 9m

    t = 10 s x = 25 m, ( ) :

    x = x x1 x = 25 9 x = 16m

    1. -, :

    t (s) 0 1 2 3 4 5 6 7 8

    u (m/s 14 14 14 11 8 5 2 2 2

  • 6

    :

    : u = 14 m/s, , -:

    a1 =

    ut

    a1 = 0

    : , - . :

    a2 =

    ut

    a2 =2146 2

    a2 = 124 a2 = 3 m / s

    2

    : u = 2 m/s, , -:

    a3 =

    ut

    a3 = 0

    2. , :

    xAB = ( ) = 2 14 xAB = 28m

    xB = ( ) =

    14+ 22

    4 xB = 32m

    x = ( ) = 2 2 x = 4m

    3. , - :

    Fx = ma2 T = ma2 T = 9N

    Fy = 0 N = mg N = 30N

    T = = T

    N = 9

    30 = 0,3

    : !