Question 888572
): over a specified distance speed varies inversely with the time.
 If a dodge viper on a test track goes a certain distance in one-half minute at 160 mph, what speed is needed to go the same distance in three-fourths minute?
:
Find the distance traveled in 30 sec (in ft)
{{{(160*5280)/3600}}} * 30 = 7040 ft
:
Let s = speed required to go 7040 ft in 45 sec
45s = 7040
s = 7040/45
s = 156.44 ft/sec
:
In mph: {{{(3600*156.44)/5280}}} = 106{{{2/3}}} mph
:
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Actually we did not have to got thru all this, use an inverse ratio relationship
{{{s/160}}} = {{{30/45}}}
Cross multiply and see what you get.