Motion Questions

April 2008             Answers are found HERE

  1. A car travels at a constant speed of 23.4 m/s for 1½ minutes. How far has it traveled?
  2. A bowling ball if thrown down a 23m alley with a constant speed of 15.5 m/s and strikes the pins. How long does it take the bowling ball to travel down the alley?
  3. A bike rider accelerates from 2.4 m/s to 12.3 m/s in 6.8s. Calculate his acceleration.
  4. How long does it take a small dog to accelerate from 1.2 m/s to 4.8 m/s, if it accelerates at a rate of 0.77 m/s?
  5. A car has an initial speed of 6.34 m/s. If it accelerates at a rate of 0.88 m/s2 for 12.7 s, how far has it traveled?
  6. Given this data:
    distance in cm
    time in s
    4
    0
    12
    4
    16
    6
    24
    10
    34
    15

    Graph this data and find the slope. What does this slope represent?
  7. A arrow is fired straight upward with an initial velocity of 35.6 m/s. If it accelerates at a rate of -9.8 m/s, how long does it take the arrow to reach its maximum height? What is the arrow's maximum height?
  8. A hockey puck has an initial velocity of 25.6 m/s and accelerates at a rate of -1.22 m/s2. If its final velocity becomes 16.4 m/s, how far has it traveled?
  9. Add these vectors:
    1. d1 = 5.5 cm [S]   d2 = 7.3 cm [N 70o W]
    2. F1 = 6.5 N [N 35o E]   F2 = 4.8 N [N 50o W]

 

Answers

All questions require a proper set up. This will not be done here; just a solution.
  1. Change 1½ to seconds ---> 90s then multiply this to 23.4 m/s to get 2106 m or 2.11 km.
  2. Another simple question. To find the time divide 23 by 15.5 to get 1.48 s.
  3. Using equation #4 subtract 2.4 from 12.3 and divide this answer by 6.8 to get 1.46 m/s2
  4. Using equation #4 subtract 1.2 from 4.8 and divide this answer by 0.77 to get 4.7 s
  5. Using equation #6 multiply 6.34 times 12.7 then add this answer to 6.34 times 12.7 squared to get 151 m
  6. A graph, slope is 2 cm/s which of course is the speed
  7. To calculate the first part use equation #4. The final velocity is 0.0 m/s at the arrow's apex. t is the unkown. a is negative. Subtract 35.6 from zero and then divide this answer by -9.8. Careful of the negative signs. The time needed to reach its maximum height is 3.36 s
    To find the distance traveled use equation #7. Be careful with the squares on v1 and v2 and with the negative signs. Multiply 2 x -9,8 and divide the answer into -(35.6)2 to get 74.5 m
  8. Use equation #7 and correctly substitute for v2, v1, and a, then solve for d.
    Distance traveled is 158 m. Obviously done on an outside pond.
  9. A vector diagram done with a ruler and a protractor.