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4.3. Practice Sets: Linear Motion

Chapter Equations

a=Δvt=vfvit   (1)

S=vi+vf2×t   (2)

S=vit+12at2   (3)

vf2=vi2+2aS   (4)

Try It!

Choose the appropriate formula from the chapter equations above for a one-step solution to the following:

  1. A cheetah reached a speed of 35m/s after covering a distance of 125m in 9.0s. What was the cheetah’s initial velocity?
  2. A streetcar starts from rest and travels 58m accelerating at a rate of 0.65m/s2. How long did it take to cover the 58m?
  3. A train is decelerating at a rate of 1.5m/s2 to a stop. If the velocity at the time it was starting to decelerate was 30m/s, find the stopping distance.

Practice

  1. A penguin slides down a glacier starting from rest and accelerates at a rate of 7.6m/s2. If it reaches the bottom of the hill travelling 15m/s, how long does it take to get to the bottom?
    Answer:

    1.97s
  2. A car slows from 45m/s to 30m/s in 6.2s. How far does it travel in that time?
    Answer:

    232.5m
  3. A cyclist speeds up from his 8.45m/s pace. As he accelerates, he travels 325m in 30s. What is his final velocity?
    Answer:

    13.2m/s
  4. If a car was going at a speed of 35m/s when it starts to decelerate at a rate of 4.64m/s2 to a complete stop, how long did it take for the car to stop?
    Answer:

    7.5s
  5. A train decelerates at a rate of 3.5m/s2 to a stop in 150m. What was the train’s speed when it started to decelerate?
    Answer:

    32.4m/s

Challenge Question(s)

Try out the two challenge questions below. Choose the best answer.

Text Version of the Challenge Question(s)
  • 1. A drag-racing car accelerates from rest at a rate of 11.0m/s2 for a distance of 120m. The car coasts for 0.75s; then the driver brakes and opens the parachute to decelerate until the end of the track. If the total length of the track is 200m, what is the minimum deceleration rate to stop before reaching the end of the track?
    Answer:11.8m/s2
  • 2. A driver is going at a constant speed of 28.0m/s. She sees a moose jump onto the road 56.0m in front of her. The driver brakes and decelerates at 7.5m/s2, stopping in front of the moose. What is the driver’s reaction time? (In other words, how long did it take the driver to react to the event prior to decelerating?)
    Answer:0.13s

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College Physics – Fundamentals and Applications Copyright © by Daniela Stanescu, Centennial College is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.