Ch. 4 Homework, Phy 131, Fall 1997, Tulane

4.1   (a) 8 m/s^2     (b) 2:1     (c) 2.67 m/s^2

4.8   Vector a = 3 i - 1.5 j (m/s^2)
      Magnitude of a = 3.4 m/s^2

4.14  (a) 490 N     (b) 110 lb

4.23  (a) 5.3 m/s^2

4.24  (a) Vector a = 2.6 i + 0.5 j (m/s^2), or  ax = 2.6 m/s^2, ay = 0.5 m/s^2
      (b) Vector sum F1+F2+F3=0
          Vector F3 = -(F1+F2) = -26 i - 5 j (N)

4.40  m = 80 kg = 180 lb,  w = 784 N,   a = 2.2 m/s^2

4.50  The scale balances the normal component of the girl's weight Wn,
      Wn = mg cos(30 deg) = 550 N, or 56 kg.