A race car accelerates uniformly as it leaves the pit area,going from rest to 32
ID: 1721839 • Letter: A
Question
A race car accelerates uniformly as it leaves the pit area,going from rest to 320 km/h in asemicircular arc with a radius of 198m.Determine the tangential acceleration of the car when it is halfwaythrough the turn, assuming constant tangential acceleration. Determine the radial acceleration of the car at this time.
If the curve were flat, what would the coefficient of staticfriction have to be between the tires and the roadbed to providethis acceleration with no slipping or skidding?
A race car accelerates uniformly as it leaves the pit area,going from rest to 320 km/h in asemicircular arc with a radius of 198m.
Determine the tangential acceleration of the car when it is halfwaythrough the turn, assuming constant tangential acceleration. Determine the radial acceleration of the car at this time.
If the curve were flat, what would the coefficient of staticfriction have to be between the tires and the roadbed to providethis acceleration with no slipping or skidding?
Explanation / Answer
Given: V= 320 km/h ( 89 m/s) R=198 m.A) Determine the tangential accelerationof the car when it is halfway through the turn, assuming constanttangential acceleration. aT= (V - 0)/ t
S= R/2 and
S= 0.5aT t2 we have
t= ( R/aT)
now
aT=V/(R/aT)
aT= V2/(R)
aT= (320 /3.6)2 / ( 198)
aT= 25.7 m/s2
B) Determine the radial acceleration ofthe car at this time. aN= V2/R aN= 89 2 / 198 aN= 40 m/s2
C) If the curve were flat, what would thecoefficient of static friction have to be between the tires and theroadbed to provide this acceleration with no slipping orskidding? f=Fc mg = mV2/R
= V2/(gR)
= 892/(9.8 x 198) =4.1
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