Practice Motion Problems

Based on using your formula sheet

  1. vavg = 65.0km/h
    t = 2.5h
    d = ?km
    vavg = d/t
    65.0 = d ÷ 2.5
    d = 65.0 X 2.5
    d = 162.5
    The distance traveled is 163 km

  2. vavg = ? m/s
    v1 = 3.44 m/s
    v2 = 12.7 m/s
    vavg = (v1 + v2)/2
    vavg = (3.44 + 12.7)/2
    = 8.07
    The average velocity or speed is 8.07 m/s.   Note the number of digits

  3. v1 = 9.5 m/s
    v2 = 2.2 m/s
    t = 3.6 s
    a = ? m/s2
    v2 = v1 + at
    2.2 = 9.5 + 3.6a
    a = (2.2 - 9.5)/3.6
    a = -2.02777    watch the negative sign in this problem.
    The acceleration is -2.0 m/s2 or the ball slows down at a rate of 2.0 m/s2

  4. v1 = 15.6 m/s
    a = 2.1 m/s2
    t = 5.3 s
    v2 ? m/s
    v2 = v1 + at
    ? = 15.6 + 2.1 x 5.3
    = 15.6 + 11.13
    = 26.73
    The final velocity is 27 m/s

  5. a = 9.8 m/s2
    t = 2.7s
    d = ? m
    v1 = 0.0 m/s (the object is dropped not thrown)
    d = v1t + ½at2
    d = 0.0 x 2.7 + ½ 9.8 x (2.7)2
        = 0.0 + 35.721
    The distance the object falls or height of the building is 35.7 m

  6. v2 = ? m/s
    v1 = 3.22 m/s
    a = 2.56 m/s2
    d = 12.8 m
    v22 = v12 + 2ad
    v22 = (3.22)2 + 2 x 2.56 x 12.8
        = 10.368 + 65.536
        = 75.904
    Now take the square root
    v2 = 8.7122
    The final velocity is 8.71 m/s
1