Answer:
6 knots
Step-by-step explanation:
Let the speed be v knots
then time taken to cover 500 M = 500 / v hrs
fuel consumption /hr = 216 + 0.5v^3
let F be the fuel consumption for trip
= [500/v][216 + 0.5v^3]
= 500[216/v + 0.5v^2]
dF/dv = 500[ - 216/v^2 + v]
d^2F/d^2v = 500[432/v^3 + 1] , i.e. +ve
so setting dF/dv will give a minima
500[ -216/v^2 + v] = 0
or v = 216/v^2
or v^3 = 216
solving, we get v = [216]^(1/3) = 6 knots
-5 because a negative plus a negative is a positive this is why it is the right answer
Answer:
s = 71 mph, and s+9 = f = 80 mph
Step-by-step explanation:
The distances the two busses travel add up to 604 mi.
Letting f be the faster speed and s the slower. Then f = s + 9 (mph).
Then (s + 9)(mph)(4 hr) + (s)(mph)(4 hr) = 604 mi. Solve this for s:
4s + 36 + 4s = 604 mi, or 8s = 568. Finally, s = 71 mph, and s+9 = f = 80 mph.
Y=1/2x+8
Step by step explanation This is how I got the answer to your question and I gave you the solution I hope this helps you out
Answer:
The answer is -9,9 Its funny cuz I just did this problem on Khan academy
Step-by-step explanation:
Can I get brainliest
