Stopping Distance, Thinking Distance, Braking Distance | GCSE Physics

00:02:32
https://www.youtube.com/watch?v=EbuR647FHh4

摘要

TLDRThis video explains the factors affecting the time it takes for a car to stop when a driver suddenly encounters an obstacle, such as a deer. The stopping distance consists of the thinking distance and the braking distance. The thinking distance depends on the driver's reaction time, which averages 0.25 seconds for visual stimuli but can be affected by tiredness, alcohol, drugs, and distractions. Professional drivers, like Formula One racers, train to minimize their reaction times. After reacting, the driver applies the brakes, initiating the braking distance, which depends on the car's speed and road conditions, such as weather and tire grip. Together, these distances form the stopping distance, which is represented as the area under a velocity-time graph.

心得

  • ⏱️ Reaction time affects stopping distance.
  • 🚗 Thinking distance occurs during driver reaction.
  • 🛑 Braking distance starts when brakes are applied.
  • 🎮 Formula One drivers practice reaction times.
  • 🤔 Tiredness increases thinking distance.
  • 🍷 Alcohol and drugs increase reaction time.
  • 📈 Stopping distance is a sum of thinking and braking distances.
  • 🛣️ Road conditions affect braking distance.
  • 📊 Velocity-time graph shows stopping distance.
  • 🎵 Distractions impact driver reaction time.

时间轴

  • 00:00:00 - 00:02:32

    Stopping distance of a car after seeing an obstacle, like a deer, is influenced by two main factors: the driver's reaction time and the car's braking distance. Average human reaction time to visual stimuli is 0.25 seconds. Various factors like lack of sleep, alcohol, drugs, or distractions can increase this reaction time. Professional drivers like Formula One racers practice improving their reaction times. After a driver reacts and applies the brakes, the car will not stop immediately but will gradually slow down due to friction between the tires and the road. This slowing distance after braking is called the braking distance, influenced by the car's speed, road conditions, and tire grip. On a velocity-time graph, the area under the curve during reaction time and braking accounts for the total stopping distance.

思维导图

Mind Map

常见问题

  • What factors determine how long it takes for a car to stop once the driver sees an obstacle?

    The two main factors are the driver's reaction time and the car's braking distance.

  • What is the average human reaction time to a visual stimulus?

    The average reaction time for a human to respond to a visual stimulus is 0.25 seconds.

  • What is thinking distance?

    The thinking distance is the distance the car travels during the driver's reaction time before the brakes are applied.

  • What is braking distance?

    Braking distance is the distance the car travels after the brakes are applied until it comes to a complete stop.

  • What factors can increase thinking distance?

    Thinking distance can be increased by tiredness, alcohol, drugs, and distractions like loud music.

  • What is stopping distance?

    Stopping distance is the sum of thinking distance and braking distance.

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  • 00:00:00
    how long does it take a car to stop if
  • 00:00:02
    the driver literally sees a deer in
  • 00:00:04
    headlights well that depends on two
  • 00:00:06
    factors first of all how quickly can to
  • 00:00:09
    drive a respond to the obstacle the
  • 00:00:11
    average reaction time for human being is
  • 00:00:14
    0.25 seconds when responding to a visual
  • 00:00:17
    stimulus but as only 0.1 7 seconds if
  • 00:00:20
    it's an audio and even less for touch
  • 00:00:23
    stimulus during the time that the
  • 00:00:25
    drivers still trying to reach this
  • 00:00:27
    situation the car keeps traveling
  • 00:00:29
    forward because he hasn't stepped on the
  • 00:00:31
    brakes just yet so he called this the
  • 00:00:33
    thinking distance if the driver didn't
  • 00:00:36
    have a good night's rest his tartness
  • 00:00:38
    will increase the thinking distance if
  • 00:00:40
    he's had some booze or tripping on drugs
  • 00:00:43
    his thinking distance will also increase
  • 00:00:45
    well yeah there are nootropics but we'll
  • 00:00:47
    save that for another time and
  • 00:00:49
    distractions like loud music and the
  • 00:00:51
    bastard car is going or the Oder driver
  • 00:00:54
    is the worst drivers reaction time would
  • 00:00:56
    be this is why Formula One car racers
  • 00:00:59
    like Lewis Hamilton constantly practice
  • 00:01:01
    improving their reaction times they
  • 00:01:04
    can't cut it down to as low as 0.2
  • 00:01:06
    seconds
  • 00:01:07
    well here's no way to practice clap your
  • 00:01:09
    hands together when you see this red
  • 00:01:11
    triangle flashes up anywhere in the
  • 00:01:13
    video now the question is what happens
  • 00:01:15
    after driver reacts and then stepped on
  • 00:01:18
    brakes the car's not going to stop
  • 00:01:20
    immediately
  • 00:01:21
    both gradually slow down because of
  • 00:01:23
    friction between the tires and the
  • 00:01:25
    ground before it finally stops the
  • 00:01:28
    distance the car travels once the brakes
  • 00:01:30
    are applied is known as the braking
  • 00:01:32
    distance the braking distance depends on
  • 00:01:35
    how fast the car is traveling and is it
  • 00:01:37
    raining is it snowing is there any
  • 00:01:40
    puddles on the road what were the
  • 00:01:41
    conditions of de brakes host a grip on
  • 00:01:44
    the tires let's plot the idea of
  • 00:01:47
    thinking distance and braking distance
  • 00:01:49
    on a velocity time graph during the
  • 00:01:51
    thinking distance the velocity remains
  • 00:01:53
    constant however during the braking
  • 00:01:56
    distance - car gradually reduces its
  • 00:01:58
    velocity we know that's the area
  • 00:02:01
    underneath a velocity time graph gives
  • 00:02:03
    us the distance travelled by the car so
  • 00:02:06
    if we add up these two areas we get
  • 00:02:09
    what's known as the stopping distance
  • 00:02:11
    this is the total distance the car
  • 00:02:13
    travels from the moments that the driver
  • 00:02:15
    reacts to when a car actually stops
  • 00:02:20
    [Music]
标签
  • stopping distance
  • reaction time
  • thinking distance
  • braking distance
  • driving safety
  • human response
  • velocity-time graph
  • Formula One
  • road conditions