Motion at changing speeds
Speed and stopping distance
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The graphs below describe the stopping process of two
heavy trucks of the same make and model: one from an initial speed of 90
km/hour, the other from an initial speed of 45 km/hour. Time
0 represents the moment when the drivers noticed the red light ahead.
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| speed (meters/second)
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time (seconds) |
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Analyze the process of stopping at different speeds
Use mathematical representations (graphs, value tables, correspondence rules)
to describe the two stopping processes. You can use the
Functions on intervals
tool from the general tools list.
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Relate your analysis to the various magnitudes important to describing the stopping process
(reaction time, braking time, stopping time, reaction distance, braking distance, stopping distance).
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Discuss in general the dependence of the
various magnitudes important to describing the stopping
process on the vehicle's speed.
Use graphs, value tables,
and correspondence rules to represent these dependences.
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In the dark, the driver's viewing
range extends at most to 100 meters, which is the range
of the headlights. What is the maximum speed
you would allow for a truck of the type considered
above to ensure that the driver is able to stop
in case a hazard lies ahead.
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