9(A) POINT VEHICLESVXQ = CARSHOUR = VX = 42 . 1 V − V 20 . 324SEEK S...

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(a) Point vehicles

vx

Q = cars

hour = v

x = 42 . 1 vv 2

0 . 324

Seek stationary point maximum

d Q

d v = 0 = 42 . 1 − 2 v

0 . 324 ∴ v * = 21 . 05 mph

Q* = 42 . 1(21 . 05) − 21 . 05 2

0 . 324 = 1367 . 6 cars/h Ans .

(b)

ll x2

1

0 . 324

Q = v

v (42 . 1) − v 2 + l

v

x + l =

Maximize Q with l = 10/5280 mi

v Q