In: Physics
There are several types of drag on a car other than air
resistance. Effects having to do with the squeezing of the tires
(rolling resistance) and frictional forces in the drivetrain (the
system that transfers energy from the engine to the rotation of the
wheels) also must be taken into account. Engineers use the
following equation to model the total force due to these different
effects
Fdrag=A+Bv+Cv2Fdrag=A+Bv+Cv2
For a Camry, these coefficients are estimated to be
A=117.130A=117.130 N, B=1.800 N s/mB=1.800 N s/m, and C=0.368 N
s2/m2C=0.368 N s2/m2.
Suppose that the driver steadily accelerates the car from 0 km/hr
to 100 km/hr over a 3.2 s. What is the magnitude of the work done
by the drag forces?
The car drives a distance 180 m up a section of road whose grade is 25% (the grade is the vertical rise of the road as a percent of the horizontal run of the road). The car's speed is 29 m/s. The car has a mass of 1543.60 kg. What is the minimum amount of power needed for the car to drive up this section of road, assuming perfect efficiency?