If we recreated the scene from Fast & Furious 7 and dropped a Challenger SRT® Hellcat Redeye Widebody from a C-130 aircraft at 5,280 ft, how much horsepower would it take to drive past it before it hits the ground if you’re 1 mile away?
- Air density @ sea level, 59 degrees, no wind = p = .002377 slugs/ft^3
- Coefficient of drag (flat plate, NASA) = C(d) = 1.28
- Weight = W = 4451 lbs
- Gravitation constant = g = 32.2 ft/sec^2
- Area = A = 197.5" long x 78.2" wide x (1 ft^2/ 144 in^2)
- Vehicle falls flat, wheels 1st, straight down, at constant acceleration with no aerodynamic drag until terminal velocity
- Horsepower needed to accelerate is AVERAGE - not peak
- 100% driveline efficiency
5 answers
1221hp
9850 HP
1221 is not correct. The answer should be 341
Vt=sqrt((2x4451)(0.002377X1.28x107.4))
107.4 is the product of (197.5 x 78.2) / 144 to find the sq ft of the car
vt=sqrt(27225)=165
tvt=165/32.2
dvt=.5X32.2X5.12^2=422
dr=5280-422=4858
tr=4858/165=29.4
aavg=2(5280)/(34.4^2)=8.87
p=((4451/32.2)X8.87X5280)/34
p=190405
hp=p/550=190405/550=346 rounding error so answer is 341 for the challenge
107.4 is the product of (197.5 x 78.2) / 144 to find the sq ft of the car
vt=sqrt(27225)=165
tvt=165/32.2
dvt=.5X32.2X5.12^2=422
dr=5280-422=4858
tr=4858/165=29.4
aavg=2(5280)/(34.4^2)=8.87
p=((4451/32.2)X8.87X5280)/34
p=190405
hp=p/550=190405/550=346 rounding error so answer is 341 for the challenge
I'm getting an answer around 389 HP which is very close to "The same amount of horsepower as a 1970 Challenger R/T" = 390 HP.