Fisica

5.- a) f = m.a          a = f/m  =  9.78m/s²

                          g = 4.89/500      =               9.78m/s²

 b) f = m.a         

    m = f/a

    m = 200/9.78m/s²  =   20.45 kg

7.-  a)  fx = m.ax   =            ax = fx/m  = -8/8  =  -1 m/s²

            fy = m.ay   =            ay = fy/m  = -8/8  =  -1 m/s²

rx = V_ox . t + ½ ax. t²                                                                  

rx = ½ (-64 m)

rx = -32

ry = V_oy . t + ½ ay. t²

rx =  ½ (0.2 m/s²) (8s)²

rx = ½ (12.8 m)

rx = 6.4 m

-32 I    +   6.4   j     m

     4 I   -    7      j     m

-28 I    -    0.6   j     m                                 R = -28 I    -    0.6   j     m                 

b)  Vx = V_o    +    ax. t                                                                             

     Vx = (-1 m/s²) (12s)

     Vx = -12 m/s

    Vy = V_o    +    ay. t                                                                             

     Vy = (0.2 m/s²) (12s)

     Vy =  2.4 m/s

R = -12 I    -    2.4   j     m