Answers to posted exam 1:
  1. a) 75.1 N
    b) 26.3 N
    c) 10a = 63.0 - T - 26.3
    d) 2a = T - 19.6
    e) a = 1.43 m/s2; T = 22.5 N

  2. (A) magnitude approx. = 7; about 25 deg. west of north

  3. a) xhobo = 3t
    b) xtrain = t + (1/2)(0.4)t2
    Hint: Solution is at xhobo = xtrain + 4.

    c) Yes; t = 2.77 s.
    d) 2.11 m/s

  4. a) v0x = 12.99 m/s; v0y = 7.5 s.
    b) H = 26.2 m
    c) D = 41.6 m

  5. a) 6432 J
    b) V = 12.7 m/s
    c) Wf = -6432 J
    d) Coeff. of friction = 0.41